feat(IgnorePlugin): allow user to provide his own check functions

The user can provide checkResource and checkContext functions that
will be called with current resource or context respectively.

These functions should return a boolean to decide whether the module
should be ignored or not.

Now the constructor can accept a single option object.

```
const resourceRegExp = /a_regex/
const contextRegExp = /another_regex/

// before:
new webpack.IgnorePlugin(resourceRegExp, contextRegExp)

// alternative:
new webpack.ignorePlugin({resourceRegExp, contextRegExp})
```

Note that from Webpack 5, only passing an object will be allowed,
so we could encourage people to migrate already.

lib/IgnorePlugin.js

@@ -4,18 +4,30 @@
 */
 "use strict";
 
+const validateOptions = require("schema-utils");
+const schema = require("../schemas/plugins/IgnorePlugin.json");
+
 /** @typedef {import("./Compiler")} Compiler */
 
 class IgnorePlugin {
 	/**
-	 * @param {RegExp} resourceRegExp A RegExp to test the request against
-	 * @param {RegExp=} contextRegExp A RegExp to test the context (directory) against
+	 * @param {object} options IgnorePlugin options
+	 * @param {RegExp} options.resourceRegExp - A RegExp to test the request against
+	 * @param {RegExp} options.contextRegExp - A RegExp to test the context (directory) against
+	 * @param {function(string): boolean=} options.checkResource - A filter function for resource
+	 * @param {function(string): boolean=} options.checkContext - A filter function for context
 	 */
-	constructor(resourceRegExp, contextRegExp) {
-		/** @private @type {RegExp} */
-		this.resourceRegExp = resourceRegExp;
-		/** @private @type {RegExp} */
-		this.contextRegExp = contextRegExp;
+	constructor(options) {
+		// TODO webpack 5 remove this compat-layer
+		if (arguments.length > 1 || options instanceof RegExp) {
+			options = {
+				resourceRegExp: arguments[0],
+				contextRegExp: arguments[1]
+			};
+		}
+
+		validateOptions(schema, options, "IgnorePlugin");
+		this.options = options;
 
 		/** @private @type {Function} */
 		this.checkIgnore = this.checkIgnore.bind(this);
@@ -27,10 +39,13 @@ class IgnorePlugin {
 	 * and the resource given matches the regexp.
 	 */
 	checkResource(resource) {
-		if (!this.resourceRegExp) {
+		if (this.options.checkResource) {
+			return this.options.checkResource(resource);
+		}
+		if (!this.options.resourceRegExp) {
 			return false;
 		}
-		return this.resourceRegExp.test(resource);
+		return this.options.resourceRegExp.test(resource);
 	}
 
 	/**
@@ -39,10 +54,14 @@ class IgnorePlugin {
 	 * or if context matches the given regexp.
 	 */
 	checkContext(context) {
-		if (!this.contextRegExp) {
+		if (this.options.checkContext) {
+			return this.options.checkContext(context);
+		}
+
+		if (!this.options.contextRegExp) {
 			return true;
 		}
-		return this.contextRegExp.test(context);
+		return this.options.contextRegExp.test(context);
 	}
 
 	/**

schemas/plugins/IgnorePlugin.json

@@ -0,0 +1,31 @@
+{
+  "type": "object",
+  "oneOf": [
+    {
+      "additionalProperties": false,
+      "properties": {
+        "resourceRegExp": {
+          "description": "A RegExp to test the request against",
+          "instanceof": "RegExp"
+        },
+        "contextRegExp": {
+          "description": "A RegExp to test the context (directory) against",
+          "instanceof": "RegExp"
+        }
+      }
+    },
+    {
+      "additionalProperties": false,
+      "properties": {
+        "checkResource": {
+          "description": "A filter function for resource",
+          "instanceof": "Function"
+        },
+        "checkContext": {
+          "description": "A filter function for context",
+          "instanceof": "Function"
+        }
+      }
+    }
+  ]
+}

test/configCases/errors/multi-entry-missing-module/webpack.config.js

@@ -7,7 +7,11 @@ module.exports = {
 	output: {
 		filename: "[name].js"
 	},
-	plugins: [new IgnorePlugin(new RegExp(/intentionally-missing-module/))],
+	plugins: [
+		new IgnorePlugin({
+			resourceRegExp: new RegExp(/intentionally-missing-module/)
+		})
+	],
 	node: {
 		__dirname: false
 	}

test/configCases/ignore/checkContextFn/folder-a/ignored-module.js

@@ -0,0 +1 @@
+module.exports = "ignored";

test/configCases/ignore/checkContextFn/folder-a/normal-module.js

@@ -0,0 +1 @@
+module.exports = require("./normal-module");

test/configCases/ignore/checkContextFn/folder-b/ignored-module.js

@@ -0,0 +1 @@
+module.exports = "ignored";

test/configCases/ignore/checkContextFn/folder-b/normal-module.js

@@ -0,0 +1 @@
+module.exports = require("./ignored-module");

test/configCases/ignore/checkContextFn/folder-b/only-context-match-require.js

@@ -0,0 +1 @@
+module.exports = "should be fine";

test/configCases/ignore/checkContextFn/folder-b/only-context-match.js

@@ -0,0 +1 @@
+module.exports = require("./only-context-match-require");

test/configCases/ignore/checkContextFn/test.js

@@ -0,0 +1,20 @@
+/* globals it */
+"use strict";
+
+it("should ignore resources that match resource regex and context", function() {
+	expect(function() {
+		require("./folder-b/normal-module");
+	}).toThrowError();
+});
+
+it("should not ignore resources that match resource but not context", function() {
+	expect(function() {
+		require("./folder-a/normal-module");
+	}).not.toThrowError();
+});
+
+it("should not ignore resources that do not match resource but do match context", function() {
+	expect(function() {
+		require("./folder-b/only-context-match");
+	}).not.toThrowError();
+});

test/configCases/ignore/checkContextFn/webpack.config.js

@@ -0,0 +1,17 @@
+"use strict";
+
+const IgnorePlugin = require("../../../../lib/IgnorePlugin");
+
+module.exports = {
+	entry: "./test.js",
+	plugins: [
+		new IgnorePlugin({
+			checkResource: function(resource) {
+				return /ignored-module/.test(resource);
+			},
+			checkContext: function(context) {
+				return /folder-b/.test(context);
+			}
+		})
+	]
+};

test/configCases/ignore/checkResourceFn/ignored-module.js

@@ -0,0 +1 @@
+module.exports = "ignored";

test/configCases/ignore/checkResourceFn/normal-module.js

@@ -0,0 +1 @@
+module.exports = "normal";

test/configCases/ignore/checkResourceFn/test.js

@@ -0,0 +1,13 @@
+/* globals it */
+"use strict";
+
+it("should ignore ignored resources", function() {
+	expect(function() {
+		require("./ignored-module");
+	}).toThrowError();
+});
+it("should not ignore resources that do not match", function() {
+	expect(function() {
+		require("./normal-module");
+	}).not.toThrowError();
+});

test/configCases/ignore/checkResourceFn/webpack.config.js

@@ -0,0 +1,14 @@
+"use strict";
+
+const IgnorePlugin = require("../../../../lib/IgnorePlugin");
+
+module.exports = {
+	entry: "./test.js",
+	plugins: [
+		new IgnorePlugin({
+			checkResource: function(resource) {
+				return /ignored-module/.test(resource);
+			}
+		})
+	]
+};

test/configCases/ignore/compatibilityLayer/folder-a/ignored-module.js

@@ -0,0 +1 @@
+module.exports = "ignored";

test/configCases/ignore/compatibilityLayer/folder-a/normal-module.js

@@ -0,0 +1 @@
+module.exports = require("./normal-module");

test/configCases/ignore/compatibilityLayer/folder-b/ignored-module.js

@@ -0,0 +1 @@
+module.exports = "ignored";

test/configCases/ignore/compatibilityLayer/folder-b/normal-module.js

@@ -0,0 +1 @@
+module.exports = require("./ignored-module");

test/configCases/ignore/compatibilityLayer/folder-b/only-context-match-require.js

@@ -0,0 +1 @@
+module.exports = "should be fine";

test/configCases/ignore/compatibilityLayer/folder-b/only-context-match.js

@@ -0,0 +1 @@
+module.exports = require("./only-context-match-require");

test/configCases/ignore/compatibilityLayer/test.js

@@ -0,0 +1,36 @@
+/* globals it */
+"use strict";
+
+// TODO: remove in webpack 5
+it("should ignore context modules that match resource regex and context (compat-layer)", function() {
+	const folderBContext = function(mod) {
+		require("./folder-b/" + mod);
+	};
+
+	expect(function() {
+		folderBContext("normal-module");
+	}).toThrowError();
+});
+
+it("should not ignore context modules that dont match the resource (compat-layer)", function() {
+	const folderBContext = function(mod) {
+		require("./folder-b/" + mod);
+	};
+
+	expect(function() {
+		folderBContext("only-context-match");
+	}).not.toThrowError();
+});
+
+it("should not ignore context modules that dont match the context (compat-layer)", function() {
+	const folderBContext = function(mod) {
+		require("./folder-a/" + mod);
+	};
+
+	expect(function() {
+		folderBContext("normal-module");
+	}).not.toThrowError();
+	expect(function() {
+		folderBContext("ignored-module");
+	}).not.toThrowError();
+});

test/configCases/ignore/compatibilityLayer/webpack.config.js

@@ -0,0 +1,8 @@
+"use strict";
+
+const IgnorePlugin = require("../../../../lib/IgnorePlugin");
+
+module.exports = {
+	entry: "./test.js",
+	plugins: [new IgnorePlugin(/ignored-module/, /folder-b/)]
+};

test/configCases/ignore/only-resource-context/webpack.config.js

@@ -4,5 +4,9 @@ const IgnorePlugin = require("../../../../lib/IgnorePlugin");
 
 module.exports = {
 	entry: "./test.js",
-	plugins: [new IgnorePlugin(/ignored-module/)]
+	plugins: [
+		new IgnorePlugin({
+			resourceRegExp: /ignored-module/
+		})
+	]
 };

test/configCases/ignore/only-resource/webpack.config.js

@@ -4,5 +4,9 @@ const IgnorePlugin = require("../../../../lib/IgnorePlugin");
 
 module.exports = {
 	entry: "./test.js",
-	plugins: [new IgnorePlugin(/ignored-module/)]
+	plugins: [
+		new IgnorePlugin({
+			resourceRegExp: /ignored-module/
+		})
+	]
 };

test/configCases/ignore/resource-and-context-contextmodule/webpack.config.js

@@ -4,5 +4,10 @@ const IgnorePlugin = require("../../../../lib/IgnorePlugin");
 
 module.exports = {
 	entry: "./test.js",
-	plugins: [new IgnorePlugin(/ignored-module/, /folder-b/)]
+	plugins: [
+		new IgnorePlugin({
+			resourceRegExp: /ignored-module/,
+			contextRegExp: /folder-b/
+		})
+	]
 };

test/configCases/ignore/resource-and-context/webpack.config.js

@@ -4,5 +4,10 @@ const IgnorePlugin = require("../../../../lib/IgnorePlugin");
 
 module.exports = {
 	entry: "./test.js",
-	plugins: [new IgnorePlugin(/ignored-module/, /folder-b/)]
+	plugins: [
+		new IgnorePlugin({
+			resourceRegExp: /ignored-module/,
+			contextRegExp: /folder-b/
+		})
+	]
 };