quotemark: Add 'no-template' option (#2766)

src/configs/all.ts

@@ -210,7 +210,12 @@ export const rules = {
     "prefer-method-signature": true,
     "prefer-switch": true,
     "prefer-template": true,
-    "quotemark": [true, "double", "avoid-escape"],
+    "quotemark": [
+        true,
+        "double",
+        "avoid-escape",
+        "avoid-template",
+    ],
     "return-undefined": true,
     "semicolon": [true, "always"],
     "space-before-function-paren": [true, {

src/rules/interfaceNameRule.ts

@@ -46,7 +46,7 @@ export class Rule extends Lint.Rules.AbstractRule {
     /* tslint:enable:object-literal-sort-keys */
 
     public static FAILURE_STRING = "interface name must start with a capitalized I";
-    public static FAILURE_STRING_NO_PREFIX = `interface name must not have an "I" prefix`;
+    public static FAILURE_STRING_NO_PREFIX = 'interface name must not have an "I" prefix';
 
     public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
         return this.applyWithFunction(sourceFile, walk, { never: this.ruleArguments.indexOf(OPTION_NEVER) !== -1 });

src/rules/interfaceOverTypeLiteralRule.ts

@@ -24,7 +24,7 @@ export class Rule extends Lint.Rules.AbstractRule {
     public static metadata: Lint.IRuleMetadata = {
         ruleName: "interface-over-type-literal",
         description: "Prefer an interface declaration over a type literal (`type T = { ... }`)",
-        rationale: `Interfaces are generally preferred over type literals because interfaces can be implemented, extended and merged.`,
+        rationale: "Interfaces are generally preferred over type literals because interfaces can be implemented, extended and merged.",
         optionsDescription: "Not configurable.",
         options: null,
         optionExamples: [true],

src/rules/maxFileLineCountRule.ts

@@ -39,7 +39,7 @@ export class Rule extends Lint.Rules.AbstractRule {
 
     public static FAILURE_STRING(lineCount: number, lineLimit: number) {
         return `This file has ${lineCount} lines, which exceeds the maximum of ${lineLimit} lines allowed. ` +
-            `Consider breaking this file up into smaller parts`;
+            "Consider breaking this file up into smaller parts";
     }
 
     public isEnabled(): boolean {

src/rules/noStringThrowRule.ts

@@ -24,8 +24,8 @@ export class Rule extends Lint.Rules.AbstractRule {
     /* tslint:disable:object-literal-sort-keys */
     public static metadata: Lint.IRuleMetadata = {
         ruleName: "no-string-throw",
-        description: `Flags throwing plain strings or concatenations of strings ` +
-            `because only Errors produce proper stack traces.`,
+        description: "Flags throwing plain strings or concatenations of strings " +
+            "because only Errors produce proper stack traces.",
         hasFix: true,
         options: null,
         optionsDescription: "Not configurable.",

src/rules/noUnnecessaryTypeAssertionRule.ts

@@ -22,7 +22,7 @@ export class Rule extends Lint.Rules.TypedRule {
     /* tslint:disable:object-literal-sort-keys */
     public static metadata: Lint.IRuleMetadata = {
         ruleName: "no-unnecessary-type-assertion",
-        description: `Warns if a type assertion does not change the type of an expression.`,
+        description: "Warns if a type assertion does not change the type of an expression.",
         options: null,
         optionsDescription: "Not configurable",
         type: "typescript",

src/rules/objectLiteralKeyQuotesRule.ts

@@ -74,7 +74,7 @@ export class Rule extends Lint.Rules.AbstractRule {
     };
     /* tslint:enable:object-literal-sort-keys */
 
-    public static INCONSISTENT_PROPERTY = `All property names in this object literal must be consistently quoted or unquoted.`;
+    public static INCONSISTENT_PROPERTY = "All property names in this object literal must be consistently quoted or unquoted.";
     public static UNNEEDED_QUOTES(name: string) {
         return `Unnecessarily quoted property '${name}' found.`;
     }

src/rules/quotemarkRule.ts

@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+import { isNoSubstitutionTemplateLiteral, isSameLine, isStringLiteral } from "tsutils";
 import * as ts from "typescript";
 
 import * as Lint from "../index";
@@ -23,12 +24,14 @@ const OPTION_SINGLE = "single";
 const OPTION_DOUBLE = "double";
 const OPTION_JSX_SINGLE = "jsx-single";
 const OPTION_JSX_DOUBLE = "jsx-double";
+const OPTION_AVOID_TEMPLATE = "avoid-template";
 const OPTION_AVOID_ESCAPE = "avoid-escape";
 
 interface Options {
-    quoteMark: string;
-    jsxQuoteMark: string;
+    quoteMark: '"' | "'";
+    jsxQuoteMark: '"' | "'";
     avoidEscape: boolean;
+    avoidTemplate: boolean;
 }
 
 export class Rule extends Lint.Rules.AbstractRule {
@@ -44,6 +47,7 @@ export class Rule extends Lint.Rules.AbstractRule {
             * \`"${OPTION_DOUBLE}"\` enforces double quotes.
             * \`"${OPTION_JSX_SINGLE}"\` enforces single quotes for JSX attributes.
             * \`"${OPTION_JSX_DOUBLE}"\` enforces double quotes for JSX attributes.
+            * \`"${OPTION_AVOID_TEMPLATE}"\` forbids single-line untagged template strings that do not contain string interpolations.
             * \`"${OPTION_AVOID_ESCAPE}"\` allows you to use the "other" quotemark in cases where escaping would normally be required.
             For example, \`[true, "${OPTION_DOUBLE}", "${OPTION_AVOID_ESCAPE}"]\` would not report a failure on the string literal
             \`'Hello "World"'\`.`,
@@ -57,7 +61,7 @@ export class Rule extends Lint.Rules.AbstractRule {
             maxLength: 5,
         },
         optionExamples: [
-            [true, OPTION_SINGLE, OPTION_AVOID_ESCAPE],
+            [true, OPTION_SINGLE, OPTION_AVOID_ESCAPE, OPTION_AVOID_TEMPLATE],
             [true, OPTION_SINGLE, OPTION_JSX_DOUBLE],
         ],
         type: "style",
@@ -75,39 +79,63 @@ export class Rule extends Lint.Rules.AbstractRule {
 
     public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
         const args = this.ruleArguments;
+        if (args.length > 0) {
+            if (args[0] !== OPTION_SINGLE && args[0] !== OPTION_DOUBLE) {
+                throw new Error(`First argument to 'quotemark' rule should be "${OPTION_SINGLE}" or "${OPTION_DOUBLE}"`);
+            }
+        }
         const quoteMark = args[0] === OPTION_SINGLE ? "'" : '"';
         return this.applyWithFunction(sourceFile, walk, {
-            avoidEscape: args.indexOf(OPTION_AVOID_ESCAPE) !== -1,
-            jsxQuoteMark: args.indexOf(OPTION_JSX_SINGLE) !== -1
-                          ? "'"
-                          : args.indexOf(OPTION_JSX_DOUBLE) !== -1 ? '"' : quoteMark,
+            avoidEscape: hasArg(OPTION_AVOID_ESCAPE),
+            avoidTemplate: hasArg(OPTION_AVOID_TEMPLATE),
+            jsxQuoteMark: hasArg(OPTION_JSX_SINGLE) ? "'" : hasArg(OPTION_JSX_DOUBLE) ? '"' : quoteMark,
             quoteMark,
         });
+
+        function hasArg(name: string): boolean {
+            return args.indexOf(name) !== -1;
+        }
     }
 }
 
 function walk(ctx: Lint.WalkContext<Options>) {
-    return ts.forEachChild(ctx.sourceFile, function cb(node: ts.Node): void {
-        if (node.kind === ts.SyntaxKind.StringLiteral) {
-            const expectedQuoteMark = node.parent!.kind === ts.SyntaxKind.JsxAttribute ? ctx.options.jsxQuoteMark : ctx.options.quoteMark;
-            const actualQuoteMark = ctx.sourceFile.text[node.end - 1];
+    const { sourceFile, options } = ctx;
+    ts.forEachChild(sourceFile, function cb(node) {
+        if (isStringLiteral(node)
+                || options.avoidTemplate && isNoSubstitutionTemplateLiteral(node)
+                && node.parent!.kind !== ts.SyntaxKind.TaggedTemplateExpression
+                && isSameLine(sourceFile, node.getStart(sourceFile), node.end)) {
+            const expectedQuoteMark = node.parent!.kind === ts.SyntaxKind.JsxAttribute ? options.jsxQuoteMark : options.quoteMark;
+            const actualQuoteMark = sourceFile.text[node.end - 1];
             if (actualQuoteMark === expectedQuoteMark) {
                 return;
             }
-            const start = node.getStart(ctx.sourceFile);
-            let text = ctx.sourceFile.text.substring(start + 1, node.end - 1);
-            if ((node as ts.StringLiteral).text.includes(expectedQuoteMark)) {
-                if (ctx.options.avoidEscape) {
+
+            let fixQuoteMark = expectedQuoteMark;
+
+            const needsQuoteEscapes = node.text.includes(expectedQuoteMark);
+            if (needsQuoteEscapes && options.avoidEscape) {
+                if (node.kind === ts.SyntaxKind.StringLiteral) {
+                    return;
+                }
+
+                // If expecting double quotes, fix a template `a "quote"` to `a 'quote'` anyway,
+                // always preferring *some* quote mark over a template.
+                fixQuoteMark = expectedQuoteMark === '"' ? "'" : '"';
+                if (node.text.includes(fixQuoteMark)) {
                     return;
                 }
-                text = text.replace(new RegExp(expectedQuoteMark, "g"), `\\${expectedQuoteMark}`);
             }
-            text = text.replace(new RegExp(`\\\\${actualQuoteMark}`, "g"), actualQuoteMark);
 
-            return ctx.addFailure(start, node.end, Rule.FAILURE_STRING(actualQuoteMark, expectedQuoteMark),
-                new Lint.Replacement(start, node.end - start, expectedQuoteMark + text + expectedQuoteMark),
-            );
+            const start = node.getStart(sourceFile);
+            let text = sourceFile.text.substring(start + 1, node.end - 1);
+            if (needsQuoteEscapes) {
+                text = text.replace(new RegExp(fixQuoteMark, "g"), `\\${fixQuoteMark}`);
+            }
+            text = text.replace(new RegExp(`\\\\${actualQuoteMark}`, "g"), actualQuoteMark);
+            return ctx.addFailure(start, node.end, Rule.FAILURE_STRING(actualQuoteMark, fixQuoteMark),
+                new Lint.Replacement(start, node.end - start, fixQuoteMark + text + fixQuoteMark));
         }
-        return ts.forEachChild(node, cb);
+        ts.forEachChild(node, cb);
     });
 }

src/test/parse.ts

@@ -61,7 +61,7 @@ export function parseErrorsFromMarkup(text: string): LintError[] {
     const lines = textWithMarkup.map(parseLine);
 
     if (lines.length > 0 && !(lines[0] instanceof CodeLine)) {
-        throw lintSyntaxError(`text cannot start with an error mark line.`);
+        throw lintSyntaxError("text cannot start with an error mark line.");
     }
 
     const messageSubstitutionLines = lines.filter((l) => l instanceof MessageSubstitutionLine) as MessageSubstitutionLine[];

test/rules/quotemark/avoid-template/test.ts.fix

@@ -0,0 +1,18 @@
+"fo`o";
+
+"a 'quote'";
+
+'a "quote"';
+
+`a "quote" 'quote'`;
+
+// Allow multi-line templates
+`
+foo
+bar
+`;
+
+// Allow tagged templates and templates with substitutions
+foo``;
+`${foo}`;
+

test/rules/quotemark/avoid-template/test.ts.lint

@@ -0,0 +1,23 @@
+`fo\`o`;
+~~~~~~~ [0]
+
+`a 'quote'`;
+~~~~~~~~~~~ [0]
+
+`a "quote"`;
+~~~~~~~~~~~ [1]
+
+`a "quote" 'quote'`;
+
+// Allow multi-line templates
+`
+foo
+bar
+`;
+
+// Allow tagged templates and templates with substitutions
+foo``;
+`${foo}`;
+
+[0]: ` should be "
+[1]: ` should be '

test/rules/quotemark/avoid-template/tslint.json

@@ -0,0 +1,5 @@
+{
+  "rules": {
+    "quotemark": [true, "double", "avoid-escape", "avoid-template"]
+  }
+}

test/rules/quotemark/double/test.ts.fix

@@ -4,3 +4,6 @@ var singleWithinDouble = "'singleWithinDouble'";
 var doubleWithinSingle = "\"doubleWithinSingle\"";
 var tabNewlineWithinSingle = "tab\tNewline\nWithinSingle";
 "escaped'quotemark";
+
+// "avoid-template" option is not set.
+`foo`;

test/rules/quotemark/double/test.ts.lint

@@ -8,3 +8,6 @@ var tabNewlineWithinSingle = 'tab\tNewline\nWithinSingle';
                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~  [' should be "]
 'escaped\'quotemark';
 ~~~~~~~~~~~~~~~~~~~~ [' should be "]
+
+// "avoid-template" option is not set.
+`foo`;