diff --git a/cli/run/batchWarnings.ts b/cli/run/batchWarnings.ts
index 8261008902e..f8850c3ca38 100644
--- a/cli/run/batchWarnings.ts
+++ b/cli/run/batchWarnings.ts
@@ -4,13 +4,13 @@ import relativeId from '../../src/utils/relativeId';
 import { stderr } from '../logging';
 
 export interface BatchWarnings {
-	add: (warning: string | RollupWarning) => void;
+	add: (warning: RollupWarning) => void;
 	readonly count: number;
 	flush: () => void;
 }
 
 export default function batchWarnings() {
-	let allWarnings = new Map<string, RollupWarning[]>();
+	let deferredWarnings = new Map<keyof typeof deferredHandlers, RollupWarning[]>();
 	let count = 0;
 
 	return {
@@ -18,65 +18,44 @@ export default function batchWarnings() {
 			return count;
 		},
 
-		add: (warning: string | RollupWarning) => {
-			if (typeof warning === 'string') {
-				warning = { code: 'UNKNOWN', message: warning };
-			}
+		add: (warning: RollupWarning) => {
+			count += 1;
 
-			if (warning.code! in immediateHandlers) {
+			if (warning.code! in deferredHandlers) {
+				if (!deferredWarnings.has(warning.code!)) deferredWarnings.set(warning.code!, []);
+				deferredWarnings.get(warning.code!)!.push(warning);
+			} else if (warning.code! in immediateHandlers) {
 				immediateHandlers[warning.code!](warning);
-				return;
-			}
+			} else {
+				title(warning.message);
 
-			if (!allWarnings.has(warning.code!)) allWarnings.set(warning.code!, []);
-			(allWarnings.get(warning.code!) as RollupWarning[]).push(warning);
+				if (warning.url) info(warning.url);
 
-			count += 1;
-		},
+				const id = (warning.loc && warning.loc.file) || warning.id;
+				if (id) {
+					const loc = warning.loc
+						? `${relativeId(id)}: (${warning.loc.line}:${warning.loc.column})`
+						: relativeId(id);
 
-		flush: () => {
-			if (count === 0) return;
-
-			const codes = Array.from(allWarnings.keys()).sort((a, b) => {
-				if (deferredHandlers[a] && deferredHandlers[b]) {
-					return deferredHandlers[a].priority - deferredHandlers[b].priority;
+					stderr(tc.bold(relativeId(loc)));
 				}
 
-				if (deferredHandlers[a]) return -1;
-				if (deferredHandlers[b]) return 1;
-				return (
-					(allWarnings.get(b) as RollupWarning[]).length -
-					(allWarnings.get(a) as RollupWarning[]).length
-				);
-			});
-
-			codes.forEach(code => {
-				const handler = deferredHandlers[code];
-				const warnings = allWarnings.get(code);
-
-				if (handler) {
-					handler.fn(warnings as RollupWarning[]);
-				} else {
-					(warnings as RollupWarning[]).forEach(warning => {
-						title(warning.message);
-
-						if (warning.url) info(warning.url);
+				if (warning.frame) info(warning.frame);
+			}
+		},
 
-						const id = (warning.loc && warning.loc.file) || warning.id;
-						if (id) {
-							const loc = warning.loc
-								? `${relativeId(id)}: (${warning.loc.line}:${warning.loc.column})`
-								: relativeId(id);
+		flush: () => {
+			if (count === 0) return;
 
-							stderr(tc.bold(relativeId(loc)));
-						}
+			const codes = Array.from(deferredWarnings.keys()).sort(
+				(a, b) => deferredWarnings.get(b)!.length - deferredWarnings.get(a)!.length
+			);
 
-						if (warning.frame) info(warning.frame);
-					});
-				}
-			});
+			for (const code of codes) {
+				deferredHandlers[code](deferredWarnings.get(code)!);
+			}
 
-			allWarnings = new Map();
+			deferredWarnings = new Map();
 			count = 0;
 		}
 	};
@@ -113,171 +92,143 @@ const immediateHandlers: {
 	}
 };
 
-// TODO select sensible priorities
 const deferredHandlers: {
-	[code: string]: {
-		fn: (warnings: RollupWarning[]) => void;
-		priority: number;
-	};
+	[code: string]: (warnings: RollupWarning[]) => void;
 } = {
-	UNUSED_EXTERNAL_IMPORT: {
-		fn: warnings => {
-			title('Unused external imports');
-			warnings.forEach(warning => {
-				stderr(`${warning.names} imported from external module '${warning.source}' but never used`);
-			});
-		},
-		priority: 1
+	CIRCULAR_DEPENDENCY(warnings) {
+		title(`Circular dependenc${warnings.length > 1 ? 'ies' : 'y'}`);
+		const displayed = warnings.length > 5 ? warnings.slice(0, 3) : warnings;
+		for (const warning of displayed) {
+			stderr(warning.cycle!.join(' -> '));
+		}
+		if (warnings.length > displayed.length) {
+			stderr(`...and ${warnings.length - displayed.length} more`);
+		}
 	},
 
-	UNRESOLVED_IMPORT: {
-		fn: warnings => {
-			title('Unresolved dependencies');
-			info('https://rollupjs.org/guide/en/#warning-treating-module-as-external-dependency');
-
-			const dependencies = new Map();
-			warnings.forEach(warning => {
-				if (!dependencies.has(warning.source)) dependencies.set(warning.source, []);
-				dependencies.get(warning.source).push(warning.importer);
-			});
-
-			Array.from(dependencies.keys()).forEach(dependency => {
-				const importers = dependencies.get(dependency);
-				stderr(`${tc.bold(dependency)} (imported by ${importers.join(', ')})`);
-			});
-		},
-		priority: 1
+	UNUSED_EXTERNAL_IMPORT(warnings) {
+		title('Unused external imports');
+		for (const warning of warnings) {
+			stderr(`${warning.names} imported from external module '${warning.source}' but never used`);
+		}
 	},
 
-	MISSING_EXPORT: {
-		fn: warnings => {
-			title('Missing exports');
-			info('https://rollupjs.org/guide/en/#error-name-is-not-exported-by-module');
+	UNRESOLVED_IMPORT(warnings) {
+		title('Unresolved dependencies');
+		info('https://rollupjs.org/guide/en/#warning-treating-module-as-external-dependency');
 
-			warnings.forEach(warning => {
-				stderr(tc.bold(warning.importer!));
-				stderr(`${warning.missing} is not exported by ${warning.exporter}`);
-				stderr(tc.gray(warning.frame!));
-			});
-		},
-		priority: 1
+		const dependencies = new Map();
+		for (const warning of warnings) {
+			if (!dependencies.has(warning.source)) dependencies.set(warning.source, []);
+			dependencies.get(warning.source).push(warning.importer);
+		}
+
+		for (const dependency of dependencies.keys()) {
+			const importers = dependencies.get(dependency);
+			stderr(`${tc.bold(dependency)} (imported by ${importers.join(', ')})`);
+		}
 	},
 
-	THIS_IS_UNDEFINED: {
-		fn: warnings => {
-			title('`this` has been rewritten to `undefined`');
-			info('https://rollupjs.org/guide/en/#error-this-is-undefined');
-			showTruncatedWarnings(warnings);
-		},
-		priority: 1
+	MISSING_EXPORT(warnings) {
+		title('Missing exports');
+		info('https://rollupjs.org/guide/en/#error-name-is-not-exported-by-module');
+
+		for (const warning of warnings) {
+			stderr(tc.bold(warning.importer!));
+			stderr(`${warning.missing} is not exported by ${warning.exporter}`);
+			stderr(tc.gray(warning.frame!));
+		}
 	},
 
-	EVAL: {
-		fn: warnings => {
-			title('Use of eval is strongly discouraged');
-			info('https://rollupjs.org/guide/en/#avoiding-eval');
-			showTruncatedWarnings(warnings);
-		},
-		priority: 1
+	THIS_IS_UNDEFINED(warnings) {
+		title('`this` has been rewritten to `undefined`');
+		info('https://rollupjs.org/guide/en/#error-this-is-undefined');
+		showTruncatedWarnings(warnings);
 	},
 
-	NON_EXISTENT_EXPORT: {
-		fn: warnings => {
-			title(`Import of non-existent ${warnings.length > 1 ? 'exports' : 'export'}`);
-			showTruncatedWarnings(warnings);
-		},
-		priority: 1
+	EVAL(warnings) {
+		title('Use of eval is strongly discouraged');
+		info('https://rollupjs.org/guide/en/#avoiding-eval');
+		showTruncatedWarnings(warnings);
 	},
 
-	NAMESPACE_CONFLICT: {
-		fn: warnings => {
-			title(`Conflicting re-exports`);
-			warnings.forEach(warning => {
-				stderr(
-					`${tc.bold(relativeId(warning.reexporter!))} re-exports '${
-						warning.name
-					}' from both ${relativeId(warning.sources![0])} and ${relativeId(
-						warning.sources![1]
-					)} (will be ignored)`
-				);
-			});
-		},
-		priority: 1
+	NON_EXISTENT_EXPORT(warnings) {
+		title(`Import of non-existent ${warnings.length > 1 ? 'exports' : 'export'}`);
+		showTruncatedWarnings(warnings);
 	},
 
-	MISSING_GLOBAL_NAME: {
-		fn: warnings => {
-			title(`Missing global variable ${warnings.length > 1 ? 'names' : 'name'}`);
+	NAMESPACE_CONFLICT(warnings) {
+		title(`Conflicting re-exports`);
+		for (const warning of warnings) {
 			stderr(
-				`Use output.globals to specify browser global variable names corresponding to external modules`
+				`${tc.bold(relativeId(warning.reexporter!))} re-exports '${
+					warning.name
+				}' from both ${relativeId(warning.sources![0])} and ${relativeId(
+					warning.sources![1]
+				)} (will be ignored)`
 			);
-			warnings.forEach(warning => {
-				stderr(`${tc.bold(warning.source!)} (guessing '${warning.guess}')`);
-			});
-		},
-		priority: 1
+		}
 	},
 
-	SOURCEMAP_BROKEN: {
-		fn: warnings => {
-			title(`Broken sourcemap`);
-			info('https://rollupjs.org/guide/en/#warning-sourcemap-is-likely-to-be-incorrect');
-
-			const plugins = Array.from(new Set(warnings.map(w => w.plugin).filter(Boolean)));
-			const detail =
-				plugins.length === 0
-					? ''
-					: plugins.length > 1
-					? ` (such as ${plugins
-							.slice(0, -1)
-							.map(p => `'${p}'`)
-							.join(', ')} and '${plugins.slice(-1)}')`
-					: ` (such as '${plugins[0]}')`;
-
-			stderr(`Plugins that transform code${detail} should generate accompanying sourcemaps`);
-		},
-		priority: 1
+	MISSING_GLOBAL_NAME(warnings) {
+		title(`Missing global variable ${warnings.length > 1 ? 'names' : 'name'}`);
+		stderr(
+			`Use output.globals to specify browser global variable names corresponding to external modules`
+		);
+		for (const warning of warnings) {
+			stderr(`${tc.bold(warning.source!)} (guessing '${warning.guess}')`);
+		}
+	},
+
+	SOURCEMAP_BROKEN(warnings) {
+		title(`Broken sourcemap`);
+		info('https://rollupjs.org/guide/en/#warning-sourcemap-is-likely-to-be-incorrect');
+
+		const plugins = Array.from(new Set(warnings.map(w => w.plugin).filter(Boolean)));
+		const detail =
+			plugins.length > 1
+				? ` (such as ${plugins
+						.slice(0, -1)
+						.map(p => `'${p}'`)
+						.join(', ')} and '${plugins.slice(-1)}')`
+				: ` (such as '${plugins[0]}')`;
+
+		stderr(`Plugins that transform code${detail} should generate accompanying sourcemaps`);
 	},
 
-	PLUGIN_WARNING: {
-		fn: warnings => {
-			const nestedByPlugin = nest(warnings, 'plugin');
+	PLUGIN_WARNING(warnings) {
+		const nestedByPlugin = nest(warnings, 'plugin');
 
-			nestedByPlugin.forEach(({ key: plugin, items }) => {
-				const nestedByMessage = nest(items, 'message');
+		for (const { key: plugin, items } of nestedByPlugin) {
+			const nestedByMessage = nest(items, 'message');
 
-				let lastUrl: string;
+			let lastUrl = '';
 
-				nestedByMessage.forEach(({ key: message, items }) => {
-					title(`Plugin ${plugin}: ${message}`);
-					items.forEach(warning => {
-						if (warning.url !== lastUrl) info((lastUrl = warning.url!));
+			for (const { key: message, items } of nestedByMessage) {
+				title(`Plugin ${plugin}: ${message}`);
+				for (const warning of items) {
+					if (warning.url && warning.url !== lastUrl) info((lastUrl = warning.url));
 
-						if (warning.id) {
-							let loc = relativeId(warning.id);
-							if (warning.loc) {
-								loc += `: (${warning.loc.line}:${warning.loc.column})`;
-							}
-							stderr(tc.bold(loc));
+					if (warning.id) {
+						let loc = relativeId(warning.id);
+						if (warning.loc) {
+							loc += `: (${warning.loc.line}:${warning.loc.column})`;
 						}
-						if (warning.frame) info(warning.frame);
-					});
-				});
-			});
-		},
-		priority: 1
+						stderr(tc.bold(loc));
+					}
+					if (warning.frame) info(warning.frame);
+				}
+			}
+		}
 	},
 
-	EMPTY_BUNDLE: {
-		fn: warnings => {
-			title(
-				`Generated${warnings.length === 1 ? ' an' : ''} empty ${
-					warnings.length > 1 ? 'chunks' : 'chunk'
-				}`
-			);
-			stderr(warnings.map(warning => warning.chunkName!).join(', '));
-		},
-		priority: 1
+	EMPTY_BUNDLE(warnings) {
+		title(
+			`Generated${warnings.length === 1 ? ' an' : ''} empty ${
+				warnings.length > 1 ? 'chunks' : 'chunk'
+			}`
+		);
+		stderr(warnings.map(warning => warning.chunkName!).join(', '));
 	}
 };
 
@@ -293,7 +244,7 @@ function nest<T>(array: T[], prop: string) {
 	const nested: { items: T[]; key: string }[] = [];
 	const lookup = new Map<string, { items: T[]; key: string }>();
 
-	array.forEach(item => {
+	for (const item of array) {
 		const key = (item as any)[prop];
 		if (!lookup.has(key)) {
 			lookup.set(key, {
@@ -301,11 +252,11 @@ function nest<T>(array: T[], prop: string) {
 				key
 			});
 
-			nested.push(lookup.get(key) as { items: T[]; key: string });
+			nested.push(lookup.get(key)!);
 		}
 
-		(lookup.get(key) as { items: T[]; key: string }).items.push(item);
-	});
+		lookup.get(key)!.items.push(item);
+	}
 
 	return nested;
 }
@@ -313,17 +264,17 @@ function nest<T>(array: T[], prop: string) {
 function showTruncatedWarnings(warnings: RollupWarning[]) {
 	const nestedByModule = nest(warnings, 'id');
 
-	const sliced = nestedByModule.length > 5 ? nestedByModule.slice(0, 3) : nestedByModule;
-	sliced.forEach(({ key: id, items }) => {
+	const displayedByModule = nestedByModule.length > 5 ? nestedByModule.slice(0, 3) : nestedByModule;
+	for (const { key: id, items } of displayedByModule) {
 		stderr(tc.bold(relativeId(id)));
 		stderr(tc.gray(items[0].frame!));
 
 		if (items.length > 1) {
 			stderr(`...and ${items.length - 1} other ${items.length > 2 ? 'occurrences' : 'occurrence'}`);
 		}
-	});
+	}
 
-	if (nestedByModule.length > sliced.length) {
-		stderr(`\n...and ${nestedByModule.length - sliced.length} other files`);
+	if (nestedByModule.length > displayedByModule.length) {
+		stderr(`\n...and ${nestedByModule.length - displayedByModule.length} other files`);
 	}
 }
diff --git a/cli/run/build.ts b/cli/run/build.ts
index ec2e5abe104..e8454e20580 100644
--- a/cli/run/build.ts
+++ b/cli/run/build.ts
@@ -81,8 +81,8 @@ export default function build(
 				}
 			}
 		})
-		.catch((err: any) => {
-			if (warnings.count > 0) warnings.flush();
+		.catch((err: Error) => {
+			warnings.flush();
 			handleError(err);
 		});
 }
diff --git a/src/Graph.ts b/src/Graph.ts
index 49c6913ddfb..68fbf33f3f4 100644
--- a/src/Graph.ts
+++ b/src/Graph.ts
@@ -395,6 +395,7 @@ export default class Graph {
 		for (const cyclePath of cyclePaths) {
 			this.warn({
 				code: 'CIRCULAR_DEPENDENCY',
+				cycle: cyclePath,
 				importer: cyclePath[0],
 				message: `Circular dependency: ${cyclePath.join(' -> ')}`
 			});
diff --git a/src/rollup/types.d.ts b/src/rollup/types.d.ts
index 6add08a8fce..6c8397dee79 100644
--- a/src/rollup/types.d.ts
+++ b/src/rollup/types.d.ts
@@ -11,6 +11,7 @@ export interface RollupError extends RollupLogProps {
 
 export interface RollupWarning extends RollupLogProps {
 	chunkName?: string;
+	cycle?: string[];
 	exporter?: string;
 	exportName?: string;
 	guess?: string;
@@ -500,10 +501,10 @@ export interface OutputOptions {
 }
 
 export type WarningHandlerWithDefault = (
-	warning: string | RollupWarning,
+	warning: RollupWarning,
 	defaultHandler: WarningHandler
 ) => void;
-export type WarningHandler = (warning: string | RollupWarning) => void;
+export type WarningHandler = (warning: RollupWarning) => void;
 
 export interface SerializedTimings {
 	[label: string]: [number, number, number];
diff --git a/src/utils/collapseSourcemaps.ts b/src/utils/collapseSourcemaps.ts
index c37b5f92aec..c20a8348fab 100644
--- a/src/utils/collapseSourcemaps.ts
+++ b/src/utils/collapseSourcemaps.ts
@@ -154,9 +154,10 @@ function getLinkMap(graph: Graph) {
 
 		graph.warn({
 			code: 'SOURCEMAP_BROKEN',
-			message: `Sourcemap is likely to be incorrect: a plugin${
-				map.plugin ? ` ('${map.plugin}')` : ``
-			} was used to transform files, but didn't generate a sourcemap for the transformation. Consult the plugin documentation for help`,
+			message:
+				`Sourcemap is likely to be incorrect: a plugin (${map.plugin}) was used to transform ` +
+				"files, but didn't generate a sourcemap for the transformation. Consult the plugin " +
+				'documentation for help',
 			plugin: map.plugin,
 			url: `https://rollupjs.org/guide/en/#warning-sourcemap-is-likely-to-be-incorrect`
 		});
diff --git a/test/cli/samples/custom-frame-log-stack/_config.js b/test/cli/samples/custom-frame-log-stack/_config.js
deleted file mode 100644
index dc959d9ab79..00000000000
--- a/test/cli/samples/custom-frame-log-stack/_config.js
+++ /dev/null
@@ -1,12 +0,0 @@
-const assert = require('assert');
-
-module.exports = {
-	description: 'errors with code frames should also log error\'s stack',
-	command: 'rollup -c',
-	error: () => true,
-	stderr: stderr => {
-		assert.ok(/custom code frame/.test(stderr));
-		assert.ok(/ at /.test(stderr));
-		assert.ok(/\.[a-z]+:\d+:\d+\)?\n/i.test(stderr));
-	}
-};
diff --git a/test/cli/samples/custom-frame-log-stack/main.js b/test/cli/samples/custom-frame-log-stack/main.js
deleted file mode 100644
index 983961490bb..00000000000
--- a/test/cli/samples/custom-frame-log-stack/main.js
+++ /dev/null
@@ -1 +0,0 @@
-console.log("everyday I'm throwing");
diff --git a/test/cli/samples/custom-frame-log-stack/rollup.config.js b/test/cli/samples/custom-frame-log-stack/rollup.config.js
deleted file mode 100644
index dcf59c3105a..00000000000
--- a/test/cli/samples/custom-frame-log-stack/rollup.config.js
+++ /dev/null
@@ -1,15 +0,0 @@
-module.exports = {
-	input: 'main.js',
-	output: {
-		format: 'cjs'
-	},
-	plugins: [
-		{
-			transform() {
-				const err = new Error('My error.');
-				err.frame = 'custom code frame';
-				this.error(err);
-			}
-		},
-	]
-};
diff --git a/test/cli/samples/custom-frame-with-pos/_config.js b/test/cli/samples/custom-frame-with-pos/_config.js
index cc92a934cee..04eb7c52a6a 100644
--- a/test/cli/samples/custom-frame-with-pos/_config.js
+++ b/test/cli/samples/custom-frame-with-pos/_config.js
@@ -1,10 +1,15 @@
-const assert = require('assert');
+const { assertStderrIncludes } = require('../../../utils.js');
 
 module.exports = {
 	description: 'custom (plugin generated) code frame taking priority over pos generated one',
 	command: 'rollup -c',
 	error: () => true,
-	stderr: stderr => {
-		assert.ok(/custom code frame/.test(stderr));
-	}
+	stderr: stderr =>
+		assertStderrIncludes(
+			stderr,
+			'[!] (plugin at position 1) Error: My error.\n' +
+				'main.js (1:5)\n' +
+				'custom code frame\n' +
+				'Error: My error.'
+		)
 };
diff --git a/test/cli/samples/custom-frame/_config.js b/test/cli/samples/custom-frame/_config.js
index bd2318495c7..1cb907bba8d 100644
--- a/test/cli/samples/custom-frame/_config.js
+++ b/test/cli/samples/custom-frame/_config.js
@@ -1,10 +1,16 @@
-const assert = require('assert');
+const { assertStderrIncludes } = require('../../../utils.js');
 
 module.exports = {
-	description: 'errors with custom (plugin generated) code frame',
+	description: 'errors with plugin generated code frames also contain stack',
 	command: 'rollup -c',
 	error: () => true,
 	stderr: stderr => {
-		assert.ok(/custom code frame/.test(stderr));
+		assertStderrIncludes(
+			stderr,
+			'[!] (plugin at position 1) Error: My error.\n' +
+				'main.js\ncustom code frame\nError: My error.\n' +
+				'    at Object.transform'
+		);
+		assertStderrIncludes(stderr, 'rollup.config.js:11:17');
 	}
 };
diff --git a/test/cli/samples/empty-chunk-multiple/_config.js b/test/cli/samples/empty-chunk-multiple/_config.js
index f2544764593..13d34e24120 100644
--- a/test/cli/samples/empty-chunk-multiple/_config.js
+++ b/test/cli/samples/empty-chunk-multiple/_config.js
@@ -1,10 +1,8 @@
-const assert = require('assert');
+const { assertStderrIncludes } = require('../../../utils.js');
 
 module.exports = {
 	description: 'shows warning when multiple chunks empty',
 	command: 'rollup -c',
 	error: () => true,
-	stderr: stderr => {
-		assert.ok(stderr.includes('(!) Generated empty chunks\na, b'));
-	}
+	stderr: stderr => assertStderrIncludes(stderr, '(!) Generated empty chunks\na, b')
 };
diff --git a/test/cli/samples/empty-chunk/_config.js b/test/cli/samples/empty-chunk/_config.js
index d6799dcc875..dca18ece281 100644
--- a/test/cli/samples/empty-chunk/_config.js
+++ b/test/cli/samples/empty-chunk/_config.js
@@ -1,10 +1,8 @@
-const assert = require('assert');
+const { assertStderrIncludes } = require('../../../utils.js');
 
 module.exports = {
 	description: 'shows warning when chunk empty',
 	command: 'rollup -c',
 	error: () => true,
-	stderr: stderr => {
-		assert.ok(stderr.includes('(!) Generated an empty chunk\nmain'));
-	}
+	stderr: stderr => assertStderrIncludes(stderr, '(!) Generated an empty chunk\nmain')
 };
diff --git a/test/cli/samples/warn-broken-sourcemap/_config.js b/test/cli/samples/warn-broken-sourcemap/_config.js
new file mode 100644
index 00000000000..596a4d33ae5
--- /dev/null
+++ b/test/cli/samples/warn-broken-sourcemap/_config.js
@@ -0,0 +1,18 @@
+const fs = require('fs');
+const path = require('path');
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'displays warnings for broken sourcemaps',
+	command: 'rollup -c',
+	stderr: stderr => {
+		fs.unlinkSync(path.resolve(__dirname, 'bundle'));
+		fs.unlinkSync(path.resolve(__dirname, 'bundle.map'));
+		assertStderrIncludes(
+			stderr,
+			'(!) Broken sourcemap\n' +
+				'https://rollupjs.org/guide/en/#warning-sourcemap-is-likely-to-be-incorrect\n' +
+				"Plugins that transform code (such as 'test-plugin1', 'test-plugin2' and 'test-plugin3') should generate accompanying sourcemaps"
+		);
+	}
+};
diff --git a/test/cli/samples/warn-broken-sourcemap/main.js b/test/cli/samples/warn-broken-sourcemap/main.js
new file mode 100644
index 00000000000..c0b933d7b56
--- /dev/null
+++ b/test/cli/samples/warn-broken-sourcemap/main.js
@@ -0,0 +1 @@
+console.log('main');
diff --git a/test/cli/samples/warn-broken-sourcemap/rollup.config.js b/test/cli/samples/warn-broken-sourcemap/rollup.config.js
new file mode 100644
index 00000000000..c490546377b
--- /dev/null
+++ b/test/cli/samples/warn-broken-sourcemap/rollup.config.js
@@ -0,0 +1,28 @@
+module.exports = {
+	input: 'main.js',
+	plugins: [
+		{
+			name: 'test-plugin1',
+			transform(code) {
+				return code + '/*1*/';
+			}
+		},
+		{
+			name: 'test-plugin2',
+			transform(code) {
+				return code + '/*2*/';
+			}
+		},
+		{
+			name: 'test-plugin3',
+			transform(code) {
+				return code + '/*3*/';
+			}
+		}
+	],
+	output: {
+		format: 'esm',
+		file: 'bundle',
+		sourcemap: true
+	}
+};
diff --git a/test/cli/samples/warn-circular-multiple/_config.js b/test/cli/samples/warn-circular-multiple/_config.js
new file mode 100644
index 00000000000..1716c598cdb
--- /dev/null
+++ b/test/cli/samples/warn-circular-multiple/_config.js
@@ -0,0 +1,16 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'warns for multiple circular dependencies',
+	command: 'rollup -c',
+	stderr: stderr =>
+		assertStderrIncludes(
+			stderr,
+			'(!) Circular dependencies\n' +
+				'main.js -> dep1.js -> main.js\n' +
+				'main.js -> dep2.js -> main.js\n' +
+				'main.js -> dep3.js -> main.js\n' +
+				'...and 3 more\n' +
+				''
+		)
+};
diff --git a/test/cli/samples/warn-circular-multiple/dep1.js b/test/cli/samples/warn-circular-multiple/dep1.js
new file mode 100644
index 00000000000..531ac38c188
--- /dev/null
+++ b/test/cli/samples/warn-circular-multiple/dep1.js
@@ -0,0 +1,2 @@
+import './main.js';
+console.log('dep1');
diff --git a/test/cli/samples/warn-circular-multiple/dep2.js b/test/cli/samples/warn-circular-multiple/dep2.js
new file mode 100644
index 00000000000..e291e1688d6
--- /dev/null
+++ b/test/cli/samples/warn-circular-multiple/dep2.js
@@ -0,0 +1,2 @@
+import './main.js';
+console.log('dep2');
diff --git a/test/cli/samples/warn-circular-multiple/dep3.js b/test/cli/samples/warn-circular-multiple/dep3.js
new file mode 100644
index 00000000000..4158ce8817f
--- /dev/null
+++ b/test/cli/samples/warn-circular-multiple/dep3.js
@@ -0,0 +1,2 @@
+import './main.js';
+console.log('dep3');
diff --git a/test/cli/samples/warn-circular-multiple/dep4.js b/test/cli/samples/warn-circular-multiple/dep4.js
new file mode 100644
index 00000000000..403fa46aa10
--- /dev/null
+++ b/test/cli/samples/warn-circular-multiple/dep4.js
@@ -0,0 +1,2 @@
+import './main.js';
+console.log('dep5');
diff --git a/test/cli/samples/warn-circular-multiple/dep5.js b/test/cli/samples/warn-circular-multiple/dep5.js
new file mode 100644
index 00000000000..403fa46aa10
--- /dev/null
+++ b/test/cli/samples/warn-circular-multiple/dep5.js
@@ -0,0 +1,2 @@
+import './main.js';
+console.log('dep5');
diff --git a/test/cli/samples/warn-circular-multiple/dep6.js b/test/cli/samples/warn-circular-multiple/dep6.js
new file mode 100644
index 00000000000..7bb212d5128
--- /dev/null
+++ b/test/cli/samples/warn-circular-multiple/dep6.js
@@ -0,0 +1,2 @@
+import './main.js';
+console.log('dep6');
diff --git a/test/cli/samples/warn-circular-multiple/main.js b/test/cli/samples/warn-circular-multiple/main.js
new file mode 100644
index 00000000000..5dfa42a26ca
--- /dev/null
+++ b/test/cli/samples/warn-circular-multiple/main.js
@@ -0,0 +1,7 @@
+import './dep1.js';
+import './dep2.js';
+import './dep3.js';
+import './dep4.js';
+import './dep5.js';
+import './dep6.js';
+console.log('main');
diff --git a/test/cli/samples/warn-circular-multiple/rollup.config.js b/test/cli/samples/warn-circular-multiple/rollup.config.js
new file mode 100644
index 00000000000..3fcdc63ccf3
--- /dev/null
+++ b/test/cli/samples/warn-circular-multiple/rollup.config.js
@@ -0,0 +1,6 @@
+module.exports = {
+	input: 'main.js',
+	output: {
+		format: 'esm'
+	}
+};
diff --git a/test/cli/samples/warn-circular/_config.js b/test/cli/samples/warn-circular/_config.js
new file mode 100644
index 00000000000..12af2aad385
--- /dev/null
+++ b/test/cli/samples/warn-circular/_config.js
@@ -0,0 +1,8 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'warns for circular dependencies',
+	command: 'rollup -c',
+	stderr: stderr =>
+		assertStderrIncludes(stderr, '(!) Circular dependency\n' + 'main.js -> dep.js -> main.js\n')
+};
diff --git a/test/cli/samples/warn-circular/dep.js b/test/cli/samples/warn-circular/dep.js
new file mode 100644
index 00000000000..6a114bf75d0
--- /dev/null
+++ b/test/cli/samples/warn-circular/dep.js
@@ -0,0 +1,2 @@
+import './main.js';
+console.log('dep');
diff --git a/test/cli/samples/warn-circular/main.js b/test/cli/samples/warn-circular/main.js
new file mode 100644
index 00000000000..16652315de2
--- /dev/null
+++ b/test/cli/samples/warn-circular/main.js
@@ -0,0 +1,2 @@
+import './dep.js';
+console.log('main');
diff --git a/test/cli/samples/warn-circular/rollup.config.js b/test/cli/samples/warn-circular/rollup.config.js
new file mode 100644
index 00000000000..3fcdc63ccf3
--- /dev/null
+++ b/test/cli/samples/warn-circular/rollup.config.js
@@ -0,0 +1,6 @@
+module.exports = {
+	input: 'main.js',
+	output: {
+		format: 'esm'
+	}
+};
diff --git a/test/cli/samples/warn-eval-multiple/_config.js b/test/cli/samples/warn-eval-multiple/_config.js
new file mode 100644
index 00000000000..70f2e45346b
--- /dev/null
+++ b/test/cli/samples/warn-eval-multiple/_config.js
@@ -0,0 +1,28 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'warns when eval is used multiple times',
+	command: 'rollup -c',
+	stderr: stderr =>
+		assertStderrIncludes(
+			stderr,
+			'(!) Use of eval is strongly discouraged\n' +
+				'https://rollupjs.org/guide/en/#avoiding-eval\n' +
+				'dep1.js\n' +
+				'1: eval(\'console.log("Hello");\');\n' +
+				'   ^\n' +
+				'dep2.js\n' +
+				'1: eval(\'console.log("Hello");\');\n' +
+				'   ^\n' +
+				'2: eval(\'console.log("Hello again");\');\n' +
+				'...and 1 other occurrence\n' +
+				'dep3.js\n' +
+				'1: eval(\'console.log("Hello");\');\n' +
+				'   ^\n' +
+				'2: eval(\'console.log("Hello again");\');\n' +
+				'3: eval(\'console.log("Hello again and again");\');\n' +
+				'...and 2 other occurrences\n' +
+				'\n' +
+				'...and 3 other files'
+		)
+};
diff --git a/test/cli/samples/warn-eval-multiple/dep1.js b/test/cli/samples/warn-eval-multiple/dep1.js
new file mode 100644
index 00000000000..a47f66e24e2
--- /dev/null
+++ b/test/cli/samples/warn-eval-multiple/dep1.js
@@ -0,0 +1 @@
+eval('console.log("Hello");');
diff --git a/test/cli/samples/warn-eval-multiple/dep2.js b/test/cli/samples/warn-eval-multiple/dep2.js
new file mode 100644
index 00000000000..f727828534e
--- /dev/null
+++ b/test/cli/samples/warn-eval-multiple/dep2.js
@@ -0,0 +1,2 @@
+eval('console.log("Hello");');
+eval('console.log("Hello again");');
diff --git a/test/cli/samples/warn-eval-multiple/dep3.js b/test/cli/samples/warn-eval-multiple/dep3.js
new file mode 100644
index 00000000000..9146f3244c8
--- /dev/null
+++ b/test/cli/samples/warn-eval-multiple/dep3.js
@@ -0,0 +1,3 @@
+eval('console.log("Hello");');
+eval('console.log("Hello again");');
+eval('console.log("Hello again and again");');
diff --git a/test/cli/samples/warn-eval-multiple/dep4.js b/test/cli/samples/warn-eval-multiple/dep4.js
new file mode 100644
index 00000000000..a47f66e24e2
--- /dev/null
+++ b/test/cli/samples/warn-eval-multiple/dep4.js
@@ -0,0 +1 @@
+eval('console.log("Hello");');
diff --git a/test/cli/samples/warn-eval-multiple/dep5.js b/test/cli/samples/warn-eval-multiple/dep5.js
new file mode 100644
index 00000000000..a47f66e24e2
--- /dev/null
+++ b/test/cli/samples/warn-eval-multiple/dep5.js
@@ -0,0 +1 @@
+eval('console.log("Hello");');
diff --git a/test/cli/samples/warn-eval-multiple/main.js b/test/cli/samples/warn-eval-multiple/main.js
new file mode 100644
index 00000000000..4ccabe761ef
--- /dev/null
+++ b/test/cli/samples/warn-eval-multiple/main.js
@@ -0,0 +1,7 @@
+import './dep1.js';
+import './dep2.js';
+import './dep3.js';
+import './dep4.js';
+import './dep5.js';
+
+eval('foo');
diff --git a/test/cli/samples/warn-eval-multiple/rollup.config.js b/test/cli/samples/warn-eval-multiple/rollup.config.js
new file mode 100644
index 00000000000..3fcdc63ccf3
--- /dev/null
+++ b/test/cli/samples/warn-eval-multiple/rollup.config.js
@@ -0,0 +1,6 @@
+module.exports = {
+	input: 'main.js',
+	output: {
+		format: 'esm'
+	}
+};
diff --git a/test/cli/samples/warn-eval/_config.js b/test/cli/samples/warn-eval/_config.js
new file mode 100644
index 00000000000..e98c7daaf7c
--- /dev/null
+++ b/test/cli/samples/warn-eval/_config.js
@@ -0,0 +1,15 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'warns when eval is used',
+	command: 'rollup -c',
+	stderr: stderr =>
+		assertStderrIncludes(
+			stderr,
+			'(!) Use of eval is strongly discouraged\n' +
+				'https://rollupjs.org/guide/en/#avoiding-eval\n' +
+				'main.js\n' +
+				"1: eval('foo');\n" +
+				'   ^'
+		)
+};
diff --git a/test/cli/samples/warn-eval/main.js b/test/cli/samples/warn-eval/main.js
new file mode 100644
index 00000000000..8c1b9dfdc37
--- /dev/null
+++ b/test/cli/samples/warn-eval/main.js
@@ -0,0 +1 @@
+eval('foo');
diff --git a/test/cli/samples/warn-eval/rollup.config.js b/test/cli/samples/warn-eval/rollup.config.js
new file mode 100644
index 00000000000..3fcdc63ccf3
--- /dev/null
+++ b/test/cli/samples/warn-eval/rollup.config.js
@@ -0,0 +1,6 @@
+module.exports = {
+	input: 'main.js',
+	output: {
+		format: 'esm'
+	}
+};
diff --git a/test/cli/samples/warn-import-export/_config.js b/test/cli/samples/warn-import-export/_config.js
new file mode 100644
index 00000000000..ac65d03491f
--- /dev/null
+++ b/test/cli/samples/warn-import-export/_config.js
@@ -0,0 +1,53 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'warns about import and export related issues',
+	command: 'rollup -c',
+	stderr: stderr => {
+		assertStderrIncludes(
+			stderr,
+			'(!) Mixing named and default exports\n' +
+				"Consumers of your bundle will have to use bundle['default'] to access the default export, which may not be what you want. Use `output.exports: 'named'` to disable this warning\n"
+		);
+		assertStderrIncludes(
+			stderr,
+			'(!) Unused external imports\n' +
+				"default imported from external module 'external' but never used\n"
+		);
+		assertStderrIncludes(
+			stderr,
+			'(!) Import of non-existent export\n' +
+				'main.js\n' +
+				"1: import unused from 'external';\n" +
+				"2: import * as dep from './dep.js';\n" +
+				"3: import alsoUnused from './dep.js';\n" +
+				'          ^\n' +
+				"4: import 'unresolvedExternal';\n"
+		);
+		assertStderrIncludes(
+			stderr,
+			'(!) Missing exports\n' +
+				'https://rollupjs.org/guide/en/#error-name-is-not-exported-by-module\n' +
+				'main.js\n' +
+				'missing is not exported by dep.js\n' +
+				"4: import 'unresolvedExternal';\n" +
+				'5: \n' +
+				'6: export const missing = dep.missing;\n' +
+				'                              ^\n' +
+				'7: export default 42;\n'
+		);
+		assertStderrIncludes(
+			stderr,
+			'(!) Conflicting re-exports\n' +
+				"main.js re-exports 'foo' from both dep.js and dep2.js (will be ignored)\n" +
+				"main.js re-exports 'bar' from both dep.js and dep2.js (will be ignored)\n"
+		);
+		assertStderrIncludes(
+			stderr,
+			'(!) Unresolved dependencies\n' +
+				'https://rollupjs.org/guide/en/#warning-treating-module-as-external-dependency\n' +
+				'unresolvedExternal (imported by main.js, dep.js)\n' +
+				'otherUnresolvedExternal (imported by dep.js)\n'
+		);
+	}
+};
diff --git a/test/cli/samples/warn-import-export/dep.js b/test/cli/samples/warn-import-export/dep.js
new file mode 100644
index 00000000000..641277b5c92
--- /dev/null
+++ b/test/cli/samples/warn-import-export/dep.js
@@ -0,0 +1,6 @@
+import 'unresolvedExternal';
+import 'otherUnresolvedExternal';
+
+export const foo = 1;
+export const bar = 2;
+export const baz = 3;
diff --git a/test/cli/samples/warn-import-export/dep2.js b/test/cli/samples/warn-import-export/dep2.js
new file mode 100644
index 00000000000..6f658e5bb4c
--- /dev/null
+++ b/test/cli/samples/warn-import-export/dep2.js
@@ -0,0 +1,3 @@
+export const foo = 4;
+export const bar = 5;
+export const quux = 6;
diff --git a/test/cli/samples/warn-import-export/main.js b/test/cli/samples/warn-import-export/main.js
new file mode 100644
index 00000000000..c58373bb0c2
--- /dev/null
+++ b/test/cli/samples/warn-import-export/main.js
@@ -0,0 +1,10 @@
+import unused from 'external';
+import * as dep from './dep.js';
+import alsoUnused from './dep.js';
+import 'unresolvedExternal';
+
+export const missing = dep.missing;
+export default 42;
+
+export * from './dep.js';
+export * from './dep2.js';
diff --git a/test/cli/samples/warn-import-export/rollup.config.js b/test/cli/samples/warn-import-export/rollup.config.js
new file mode 100644
index 00000000000..13535909996
--- /dev/null
+++ b/test/cli/samples/warn-import-export/rollup.config.js
@@ -0,0 +1,7 @@
+module.exports = {
+	input: 'main.js',
+	external: ['external'],
+	output: {
+		format: 'cjs'
+	}
+};
diff --git a/test/cli/samples/warn-missing-global-multiple/_config.js b/test/cli/samples/warn-missing-global-multiple/_config.js
new file mode 100644
index 00000000000..4d6e61c9997
--- /dev/null
+++ b/test/cli/samples/warn-missing-global-multiple/_config.js
@@ -0,0 +1,15 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'warns when there are multiple missing globals',
+	command: 'rollup -c',
+	stderr: stderr =>
+		assertStderrIncludes(
+			stderr,
+			'(!) Missing global variable names\n' +
+				'Use output.globals to specify browser global variable names corresponding to external modules\n' +
+				"external1 (guessing 'foo1')\n" +
+				"external2 (guessing 'foo2')\n" +
+				"external3 (guessing 'foo3')"
+		)
+};
diff --git a/test/cli/samples/warn-missing-global-multiple/main.js b/test/cli/samples/warn-missing-global-multiple/main.js
new file mode 100644
index 00000000000..ff620a05cd7
--- /dev/null
+++ b/test/cli/samples/warn-missing-global-multiple/main.js
@@ -0,0 +1,5 @@
+import foo1 from 'external1';
+import foo2 from 'external2';
+import foo3 from 'external3';
+
+console.log(foo1, foo2, foo3);
diff --git a/test/cli/samples/warn-missing-global-multiple/rollup.config.js b/test/cli/samples/warn-missing-global-multiple/rollup.config.js
new file mode 100644
index 00000000000..671f387f3cb
--- /dev/null
+++ b/test/cli/samples/warn-missing-global-multiple/rollup.config.js
@@ -0,0 +1,8 @@
+module.exports = {
+	input: 'main.js',
+	external: ['external1', 'external2', 'external3'],
+	output: {
+		format: 'iife',
+		name: 'bundle'
+	}
+};
diff --git a/test/cli/samples/warn-missing-global/_config.js b/test/cli/samples/warn-missing-global/_config.js
new file mode 100644
index 00000000000..74a84a6cde1
--- /dev/null
+++ b/test/cli/samples/warn-missing-global/_config.js
@@ -0,0 +1,13 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'warns when there is a missing global variable name',
+	command: 'rollup -c',
+	stderr: stderr =>
+		assertStderrIncludes(
+			stderr,
+			'(!) Missing global variable name\n' +
+				'Use output.globals to specify browser global variable names corresponding to external modules\n' +
+				"external (guessing 'foo')"
+		)
+};
diff --git a/test/cli/samples/warn-missing-global/main.js b/test/cli/samples/warn-missing-global/main.js
new file mode 100644
index 00000000000..96decbbc428
--- /dev/null
+++ b/test/cli/samples/warn-missing-global/main.js
@@ -0,0 +1,2 @@
+import foo from 'external';
+console.log(foo);
diff --git a/test/cli/samples/warn-missing-global/rollup.config.js b/test/cli/samples/warn-missing-global/rollup.config.js
new file mode 100644
index 00000000000..4241f975e8c
--- /dev/null
+++ b/test/cli/samples/warn-missing-global/rollup.config.js
@@ -0,0 +1,8 @@
+module.exports = {
+	input: 'main.js',
+	external: ['external'],
+	output: {
+		format: 'iife',
+		name: 'bundle'
+	}
+};
diff --git a/test/cli/samples/warn-multiple/_config.js b/test/cli/samples/warn-multiple/_config.js
new file mode 100644
index 00000000000..b59306033c9
--- /dev/null
+++ b/test/cli/samples/warn-multiple/_config.js
@@ -0,0 +1,35 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'aggregates warnings of different types',
+	command: 'rollup -c',
+	stderr: stderr => {
+		assertStderrIncludes(
+			stderr,
+			'(!) Missing shims for Node.js built-ins\n' +
+				"Creating a browser bundle that depends on 'url', 'assert' and 'path'. You might need to include https://www.npmjs.com/package/rollup-plugin-node-builtins\n"
+		);
+		assertStderrIncludes(
+			stderr,
+			'(!) Import of non-existent exports\n' +
+				'main.js\n' +
+				"4: import assert from 'assert';\n" +
+				"5: import path from 'path';\n" +
+				"6: import {doesNotExist, alsoNotFound} from './dep.js';\n" +
+				'           ^\n' +
+				'7: \n' +
+				'8: export {url, assert, path};\n' +
+				'...and 1 other occurrence\n'
+		);
+		assertStderrIncludes(
+			stderr,
+
+			"(!) Module level directives cause errors when bundled, 'use stuff' was ignored.\n" +
+				'main.js: (1:0)\n' +
+				"1: 'use stuff';\n" +
+				'   ^\n' +
+				'2: \n' +
+				"3: import url from 'url';\n"
+		);
+	}
+};
diff --git a/test/cli/samples/warn-multiple/dep.js b/test/cli/samples/warn-multiple/dep.js
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/test/cli/samples/warn-multiple/main.js b/test/cli/samples/warn-multiple/main.js
new file mode 100644
index 00000000000..809f20ffe84
--- /dev/null
+++ b/test/cli/samples/warn-multiple/main.js
@@ -0,0 +1,8 @@
+'use stuff';
+
+import url from 'url';
+import assert from 'assert';
+import path from 'path';
+import {doesNotExist, alsoNotFound} from './dep.js';
+
+export {url, assert, path};
diff --git a/test/cli/samples/warn-multiple/rollup.config.js b/test/cli/samples/warn-multiple/rollup.config.js
new file mode 100644
index 00000000000..74772f14525
--- /dev/null
+++ b/test/cli/samples/warn-multiple/rollup.config.js
@@ -0,0 +1,8 @@
+module.exports = {
+	input: 'main.js',
+	external: ['url', 'assert', 'path'],
+	output: {
+		name: 'bundle',
+		format: 'amd'
+	}
+};
diff --git a/test/cli/samples/warn-plugin/_config.js b/test/cli/samples/warn-plugin/_config.js
new file mode 100644
index 00000000000..0815e2feca6
--- /dev/null
+++ b/test/cli/samples/warn-plugin/_config.js
@@ -0,0 +1,18 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'displays warnings from plugins',
+	command: 'rollup -c',
+	stderr: stderr =>
+		assertStderrIncludes(
+			stderr,
+			'(!) Plugin test-plugin: First\n' +
+				'(!) Plugin test-plugin: Second\n' +
+				'https://information\n' +
+				'(!) Plugin second-plugin: Third\n' +
+				'other.js\n' +
+				'(!) Plugin second-plugin: Fourth\n' +
+				'other.js: (1:2)\n' +
+				'custom frame'
+		)
+};
diff --git a/test/cli/samples/warn-plugin/main.js b/test/cli/samples/warn-plugin/main.js
new file mode 100644
index 00000000000..c0b933d7b56
--- /dev/null
+++ b/test/cli/samples/warn-plugin/main.js
@@ -0,0 +1 @@
+console.log('main');
diff --git a/test/cli/samples/warn-plugin/rollup.config.js b/test/cli/samples/warn-plugin/rollup.config.js
new file mode 100644
index 00000000000..bd985d99739
--- /dev/null
+++ b/test/cli/samples/warn-plugin/rollup.config.js
@@ -0,0 +1,32 @@
+const path = require('path');
+
+module.exports = {
+	input: 'main.js',
+	plugins: [
+		{
+			name: 'test-plugin',
+			buildStart() {
+				this.warn('First');
+				this.warn({ message: 'Second', url: 'https://information' });
+				this.warn({ message: 'Second', url: 'https://information' });
+			}
+		}
+	],
+	output: {
+		format: 'esm',
+		plugins: [
+			{
+				name: 'second-plugin',
+				renderStart() {
+					this.warn({ message: 'Third', id: path.resolve(__dirname, 'other.js') });
+					this.warn({
+						message: 'Fourth',
+						id: path.resolve(__dirname, 'other.js'),
+						loc: { line: 1, column: 2 },
+						frame: 'custom frame'
+					});
+				}
+			}
+		]
+	}
+};
diff --git a/test/cli/samples/warn-this/_config.js b/test/cli/samples/warn-this/_config.js
new file mode 100644
index 00000000000..fe2ff4656de
--- /dev/null
+++ b/test/cli/samples/warn-this/_config.js
@@ -0,0 +1,15 @@
+const { assertStderrIncludes } = require('../../../utils.js');
+
+module.exports = {
+	description: 'warns "this" is used on the top level',
+	command: 'rollup -c',
+	stderr: stderr =>
+		assertStderrIncludes(
+			stderr,
+			'(!) `this` has been rewritten to `undefined`\n' +
+				'https://rollupjs.org/guide/en/#error-this-is-undefined\n' +
+				'main.js\n' +
+				'1: console.log(this);\n' +
+				'               ^'
+		)
+};
diff --git a/test/cli/samples/warn-this/main.js b/test/cli/samples/warn-this/main.js
new file mode 100644
index 00000000000..4593c7185d1
--- /dev/null
+++ b/test/cli/samples/warn-this/main.js
@@ -0,0 +1 @@
+console.log(this);
diff --git a/test/cli/samples/warn-this/rollup.config.js b/test/cli/samples/warn-this/rollup.config.js
new file mode 100644
index 00000000000..4241f975e8c
--- /dev/null
+++ b/test/cli/samples/warn-this/rollup.config.js
@@ -0,0 +1,8 @@
+module.exports = {
+	input: 'main.js',
+	external: ['external'],
+	output: {
+		format: 'iife',
+		name: 'bundle'
+	}
+};
diff --git a/test/function/samples/already-deshadowed-import/_config.js b/test/function/samples/already-deshadowed-import/_config.js
index 072b6459647..b8ce432d1ac 100644
--- a/test/function/samples/already-deshadowed-import/_config.js
+++ b/test/function/samples/already-deshadowed-import/_config.js
@@ -4,6 +4,7 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['bob.js', 'alice.js', 'bob.js'],
 			importer: 'bob.js',
 			message: 'Circular dependency: bob.js -> alice.js -> bob.js'
 		}
diff --git a/test/function/samples/can-import-self-treeshake/_config.js b/test/function/samples/can-import-self-treeshake/_config.js
index 98770762cfd..7873b58b34a 100644
--- a/test/function/samples/can-import-self-treeshake/_config.js
+++ b/test/function/samples/can-import-self-treeshake/_config.js
@@ -3,6 +3,7 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['lib.js', 'lib.js'],
 			importer: 'lib.js',
 			message: 'Circular dependency: lib.js -> lib.js'
 		},
diff --git a/test/function/samples/can-import-self/_config.js b/test/function/samples/can-import-self/_config.js
index 5e99b362146..f49dfc06ef3 100644
--- a/test/function/samples/can-import-self/_config.js
+++ b/test/function/samples/can-import-self/_config.js
@@ -8,6 +8,7 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['lib.js', 'lib.js'],
 			importer: 'lib.js',
 			message: 'Circular dependency: lib.js -> lib.js'
 		}
diff --git a/test/function/samples/compact/_config.js b/test/function/samples/compact/_config.js
index 8a330e31a45..e41b7457fa6 100644
--- a/test/function/samples/compact/_config.js
+++ b/test/function/samples/compact/_config.js
@@ -10,6 +10,7 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['main.js', 'main.js'],
 			importer: 'main.js',
 			message: 'Circular dependency: main.js -> main.js'
 		}
diff --git a/test/function/samples/cycles-default-anonymous-function-hoisted/_config.js b/test/function/samples/cycles-default-anonymous-function-hoisted/_config.js
index 00a6286e004..60e42dcfb98 100644
--- a/test/function/samples/cycles-default-anonymous-function-hoisted/_config.js
+++ b/test/function/samples/cycles-default-anonymous-function-hoisted/_config.js
@@ -3,6 +3,7 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['f.js', 'g.js', 'f.js'],
 			importer: 'f.js',
 			message: 'Circular dependency: f.js -> g.js -> f.js'
 		}
diff --git a/test/function/samples/cycles-defaults/_config.js b/test/function/samples/cycles-defaults/_config.js
index 9ead90eb736..84969a977d2 100644
--- a/test/function/samples/cycles-defaults/_config.js
+++ b/test/function/samples/cycles-defaults/_config.js
@@ -3,6 +3,7 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['a.js', 'b.js', 'a.js'],
 			importer: 'a.js',
 			message: 'Circular dependency: a.js -> b.js -> a.js'
 		}
diff --git a/test/function/samples/cycles-export-star/_config.js b/test/function/samples/cycles-export-star/_config.js
index c58ddefedd0..b1f63718246 100644
--- a/test/function/samples/cycles-export-star/_config.js
+++ b/test/function/samples/cycles-export-star/_config.js
@@ -11,6 +11,7 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['a.js', 'b.js', 'a.js'],
 			importer: 'a.js',
 			message: 'Circular dependency: a.js -> b.js -> a.js'
 		}
diff --git a/test/function/samples/cycles-immediate/_config.js b/test/function/samples/cycles-immediate/_config.js
index a1d17e7c191..8c4b9235fd3 100644
--- a/test/function/samples/cycles-immediate/_config.js
+++ b/test/function/samples/cycles-immediate/_config.js
@@ -3,6 +3,7 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['evens.js', 'odds.js', 'evens.js'],
 			importer: 'evens.js',
 			message: 'Circular dependency: evens.js -> odds.js -> evens.js'
 		}
diff --git a/test/function/samples/cycles-pathological-2/_config.js b/test/function/samples/cycles-pathological-2/_config.js
index e915af535e9..727ee735637 100644
--- a/test/function/samples/cycles-pathological-2/_config.js
+++ b/test/function/samples/cycles-pathological-2/_config.js
@@ -4,16 +4,19 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['main.js', 'b.js', 'main.js'],
 			importer: 'main.js',
 			message: 'Circular dependency: main.js -> b.js -> main.js'
 		},
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['b.js', 'd.js', 'c.js', 'b.js'],
 			importer: 'b.js',
 			message: 'Circular dependency: b.js -> d.js -> c.js -> b.js'
 		},
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['main.js', 'b.js', 'd.js', 'c.js', 'main.js'],
 			importer: 'main.js',
 			message: 'Circular dependency: main.js -> b.js -> d.js -> c.js -> main.js'
 		}
diff --git a/test/function/samples/cycles-stack-overflow/_config.js b/test/function/samples/cycles-stack-overflow/_config.js
index a56497ef845..7c01540e491 100644
--- a/test/function/samples/cycles-stack-overflow/_config.js
+++ b/test/function/samples/cycles-stack-overflow/_config.js
@@ -3,11 +3,13 @@ module.exports = {
 	warnings: [
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['c.js', 'd.js', 'b.js', 'c.js'],
 			importer: 'c.js',
 			message: 'Circular dependency: c.js -> d.js -> b.js -> c.js'
 		},
 		{
 			code: 'CIRCULAR_DEPENDENCY',
+			cycle: ['c.js', 'd.js', 'c.js'],
 			importer: 'c.js',
 			message: 'Circular dependency: c.js -> d.js -> c.js'
 		}
diff --git a/test/sourcemaps/samples/deprecated/transform-without-sourcemap/_config.js b/test/sourcemaps/samples/deprecated/transform-without-sourcemap/_config.js
index 0e08b7d75fc..7c99723aa26 100644
--- a/test/sourcemaps/samples/deprecated/transform-without-sourcemap/_config.js
+++ b/test/sourcemaps/samples/deprecated/transform-without-sourcemap/_config.js
@@ -30,7 +30,7 @@ module.exports = {
 		{
 			code: `SOURCEMAP_BROKEN`,
 			plugin: 'fake plugin 1',
-			message: `Sourcemap is likely to be incorrect: a plugin ('fake plugin 1') was used to transform files, but didn't generate a sourcemap for the transformation. Consult the plugin documentation for help`,
+			message: `Sourcemap is likely to be incorrect: a plugin (fake plugin 1) was used to transform files, but didn't generate a sourcemap for the transformation. Consult the plugin documentation for help`,
 			url: `https://rollupjs.org/guide/en/#warning-sourcemap-is-likely-to-be-incorrect`
 		}
 	]
diff --git a/test/sourcemaps/samples/transform-without-sourcemap-render-chunk/_config.js b/test/sourcemaps/samples/transform-without-sourcemap-render-chunk/_config.js
index 703d4c85cad..ca874293a6a 100644
--- a/test/sourcemaps/samples/transform-without-sourcemap-render-chunk/_config.js
+++ b/test/sourcemaps/samples/transform-without-sourcemap-render-chunk/_config.js
@@ -23,7 +23,7 @@ module.exports = {
 		{
 			code: `SOURCEMAP_BROKEN`,
 			plugin: 'fake plugin 1',
-			message: `Sourcemap is likely to be incorrect: a plugin ('fake plugin 1') was used to transform files, but didn't generate a sourcemap for the transformation. Consult the plugin documentation for help`,
+			message: `Sourcemap is likely to be incorrect: a plugin (fake plugin 1) was used to transform files, but didn't generate a sourcemap for the transformation. Consult the plugin documentation for help`,
 			url: `https://rollupjs.org/guide/en/#warning-sourcemap-is-likely-to-be-incorrect`
 		}
 	]
diff --git a/test/test.js b/test/test.js
index 366ad843275..215525dbb9e 100644
--- a/test/test.js
+++ b/test/test.js
@@ -3,11 +3,6 @@ require('console-group').install();
 
 describe('rollup', function() {
 	this.timeout(10000);
-
-	// To quickly check the effects of potential performance improvements
-	before(() => console.time('Total test time'));
-	after(() => console.timeEnd('Total test time'));
-
 	require('./misc/index.js');
 	require('./function/index.js');
 	require('./form/index.js');
diff --git a/test/utils.js b/test/utils.js
index b8159f292c2..57791247fdb 100644
--- a/test/utils.js
+++ b/test/utils.js
@@ -12,6 +12,7 @@ exports.loader = loader;
 exports.normaliseOutput = normaliseOutput;
 exports.runTestSuiteWithSamples = runTestSuiteWithSamples;
 exports.assertDirectoriesAreEqual = assertDirectoriesAreEqual;
+exports.assertStderrIncludes = assertStderrIncludes;
 
 function normaliseError(error) {
 	delete error.stack;
@@ -224,3 +225,12 @@ function assertFilesAreEqual(actualFiles, expectedFiles, dirs = []) {
 		);
 	});
 }
+
+function assertStderrIncludes(stderr, expected) {
+	// eslint-disable-next-line no-control-regex
+	const output = stderr.replace(/\x1b\[[^m]*m/g, '');
+	assert.ok(
+		output.includes(expected),
+		`Could not find ${JSON.stringify(expected)} in ${JSON.stringify(output)}`
+	);
+}