Excuse edge cases in quotemark backtick (#4588) (#4618)

This commit fixes the cases where export statements, string literal type as generic type parameter, and string literals in object literal property assignments were incorrectly flagged. This also fixes a small lint error (specifying a type parameter same as default).

src/rules/noNullUndefinedUnionRule.ts

@@ -55,7 +55,7 @@ export class Rule extends Lint.Rules.TypedRule {
     }
 }
 
-function walk(ctx: Lint.WalkContext<void>, tc: ts.TypeChecker): void {
+function walk(ctx: Lint.WalkContext, tc: ts.TypeChecker): void {
     return ts.forEachChild(ctx.sourceFile, function cb(node: ts.Node): void {
         const type = getType(node, tc);
         if (type !== undefined && isNullUndefinedUnion(type)) {

src/rules/quotemarkRule.ts

@@ -15,9 +15,9 @@
  * limitations under the License.
  */
 import {
+    isExportDeclaration,
     isImportDeclaration,
     isNoSubstitutionTemplateLiteral,
-    isPropertyAssignment,
     isSameLine,
     isStringLiteral,
 } from "tsutils";
@@ -130,20 +130,37 @@ function walk(ctx: Lint.WalkContext<Options>) {
             // Don't use backticks instead of single/double quotes when it breaks TypeScript syntax.
             if (
                 expectedQuotemark === "`" &&
-                (isImportDeclaration(node.parent) || isPropertyAssignment(node.parent))
+                // This captures `export blah from "package"`
+                (isExportDeclaration(node.parent) ||
+                    // This captures `import blah from "package"`
+                    isImportDeclaration(node.parent) ||
+                    // This captures kebab-case property names in object literals (only when the node is not at the end of the parent node)
+                    (node.parent.kind === ts.SyntaxKind.PropertyAssignment &&
+                        node.end !== node.parent.end) ||
+                    // This captures the kebab-case property names in type definitions
+                    node.parent.kind === ts.SyntaxKind.PropertySignature ||
+                    // This captures literal types in generic type constraints
+                    node.parent.parent.kind === ts.SyntaxKind.TypeReference)
             ) {
                 return;
             }
 
+            // We already have the expected quotemark. Done.
             if (actualQuotemark === expectedQuotemark) {
                 return;
             }
 
+            /** The quotemark we intend to use to fix this node. */
             let fixQuotemark = expectedQuotemark;
-            const needsQuoteEscapes = node.text.includes(expectedQuotemark);
+
+            /**
+             * Whether this node needs to be escaped (because
+             *   it contains the expected quotemark).
+             */
+            const needsToBeEscaped = node.text.includes(expectedQuotemark);
 
             // This string requires escapes to use the expected quote mark, but `avoid-escape` was passed
-            if (needsQuoteEscapes && options.avoidEscape) {
+            if (needsToBeEscaped && options.avoidEscape) {
                 if (node.kind === ts.SyntaxKind.StringLiteral) {
                     return;
                 }
@@ -153,7 +170,7 @@ function walk(ctx: Lint.WalkContext<Options>) {
                 const alternativeFixQuotemark = expectedQuotemark === '"' ? "'" : '"';
 
                 if (node.text.includes(alternativeFixQuotemark)) {
-                    // It also includes the alternative fix quote mark. Let's try to use single quotes instead,
+                    // It also includes the alternative fix quotemark. Let's try to use single quotes instead,
                     // unless we originally expected single quotes, in which case we will try to use backticks.
                     // This means that we may use backtick even with avoid-template in trying to avoid escaping.
                     fixQuotemark = expectedQuotemark === "'" ? "`" : "'";
@@ -173,7 +190,7 @@ function walk(ctx: Lint.WalkContext<Options>) {
             const start = node.getStart(sourceFile);
             let text = sourceFile.text.substring(start + 1, node.end - 1);
 
-            if (needsQuoteEscapes) {
+            if (needsToBeEscaped) {
                 text = text.replace(new RegExp(fixQuotemark, "g"), `\\${fixQuotemark}`);
             }
 
@@ -186,6 +203,7 @@ function walk(ctx: Lint.WalkContext<Options>) {
                 new Lint.Replacement(start, node.end - start, fixQuotemark + text + fixQuotemark),
             );
         }
+
         ts.forEachChild(node, cb);
     });
 }

test/rules/quotemark/backtick/test.ts.fix

@@ -1,13 +1,26 @@
 import { Something } from "some-package"
+export { SomethingElse } from "another-package"
 
 var single = `single`;
     var double = `married`;
 var singleWithinDouble = `'singleWithinDouble'`;
 var doubleWithinSingle = `"doubleWithinSingle"`;
 var tabNewlineWithinSingle = `tab\tNewline\nWithinSingle`;
+var array: Array<"literal string"> = [];
+var hello: `world`;
 `escaped'quotemark`;
 
 // "avoid-template" option is not set.
 `foo`;
 
-const object = { "kebab-case": 3 }
+const object: {
+    "hello-kebab"
+    : number
+    "kebab-case": number
+    "another-kebab": `hello-value`
+} = {
+    "hello-kebab"
+    : 4
+    "kebab-case": 3,
+    "another-kebab": `hello-value`
+};

test/rules/quotemark/backtick/test.ts.lint

@@ -1,4 +1,5 @@
 import { Something } from "some-package"
+export { SomethingElse } from "another-package"
 
 var single = 'single';
              ~~~~~~~~  [' should be `]
@@ -10,10 +11,25 @@ var doubleWithinSingle = '"doubleWithinSingle"';
                          ~~~~~~~~~~~~~~~~~~~~~~  [' should be `]
 var tabNewlineWithinSingle = 'tab\tNewline\nWithinSingle';
                              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~  [' should be `]
+var array: Array<"literal string"> = [];
+var hello: "world";
+           ~~~~~~~ [" should be `]
 'escaped\'quotemark';
 ~~~~~~~~~~~~~~~~~~~~ [' should be `]
 
 // "avoid-template" option is not set.
 `foo`;
 
-const object = { "kebab-case": 3 }
+const object: {
+    "hello-kebab"
+    : number
+    "kebab-case": number
+    "another-kebab": "hello-value"
+                     ~~~~~~~~~~~~~ [" should be `]
+} = {
+    "hello-kebab"
+    : 4
+    "kebab-case": 3,
+    "another-kebab": "hello-value"
+                     ~~~~~~~~~~~~~ [" should be `]
+};