tests(ast-spec): make PunctuatorTokenToText more type-safe (typescript-eslint#3529)

MichaelDeBoey · web-flow · commit abda9614e944 · 2021-06-21T00:33:57.000-07:00
diff --git a/packages/ast-spec/src/token/PunctuatorToken/PunctuatorTokenToText.ts b/packages/ast-spec/src/token/PunctuatorToken/PunctuatorTokenToText.ts
@@ -44,6 +44,8 @@ export interface PunctuatorTokenToText {
   [SyntaxKind.ColonToken]: ':';
   [SyntaxKind.AtToken]: '@';
   [SyntaxKind.QuestionQuestionToken]: '??';
+  [SyntaxKind.BacktickToken]: '`';
+  // [SyntaxKind.HashToken]: '#'; // new in PunctuationSyntaxKind in TS 4.4
   [SyntaxKind.EqualsToken]: '=';
   [SyntaxKind.PlusEqualsToken]: '+=';
   [SyntaxKind.MinusEqualsToken]: '-=';
@@ -56,8 +58,8 @@ export interface PunctuatorTokenToText {
   [SyntaxKind.GreaterThanGreaterThanGreaterThanEqualsToken]: '>>>=';
   [SyntaxKind.AmpersandEqualsToken]: '&=';
   [SyntaxKind.BarEqualsToken]: '|=';
-  [SyntaxKind.BarBarEqualsToken]: '||=';
-  [SyntaxKind.AmpersandAmpersandEqualsToken]: '&&=';
-  [SyntaxKind.QuestionQuestionEqualsToken]: '??=';
+  [SyntaxKind.BarBarEqualsToken]: '||='; // included in PunctuationSyntaxKind in TS 4.4
+  [SyntaxKind.AmpersandAmpersandEqualsToken]: '&&='; // included in PunctuationSyntaxKind in TS 4.4
+  [SyntaxKind.QuestionQuestionEqualsToken]: '??='; // included in PunctuationSyntaxKind in TS 4.4
   [SyntaxKind.CaretEqualsToken]: '^=';
 }
diff --git a/packages/ast-spec/tests/PunctuatorTokenToText.test.ts b/packages/ast-spec/tests/PunctuatorTokenToText.test.ts
@@ -0,0 +1,11 @@
+import type { PunctuationSyntaxKind } from 'typescript';
+
+import type { PunctuatorTokenToText } from '../src';
+
+// @ts-expect-error: purposely unused
+type _Test = {
+  readonly [T in PunctuationSyntaxKind]: PunctuatorTokenToText[T];
+  // If there are any PunctuationSyntaxKind members that don't have a
+  // corresponding PunctuatorTokenToText, then this line will error with
+  // "Type 'T' cannot be used to index type 'PunctuatorTokenToText'."
+};
