optimize: ensure with new fix that we avoid checking back too far

Author: brettz9

README.md

@@ -10565,6 +10565,13 @@ export class User {
 }
 // Options: [{"contexts":["ClassProperty:has(Decorator[expression.callee.name=\"Input\"])"]}]
 // Message: Missing JSDoc comment.
+
+@Input()
+export class UserSettingsState {
+  method () {}
+}
+// Options: [{"require":{"MethodDefinition":true}}]
+// Message: Missing JSDoc comment.
 ````
 
 The following patterns are not considered problems:

src/eslint/getJSDocComment.js

@@ -16,23 +16,29 @@ const isCommentToken = (token) => {
 
 const decoratorMetaTokens = new Map([[')', '('], ['>', '<']]);
 
+// eslint-disable-next-line complexity
 const getDecorator = (token, sourceCode) => {
   if (!token) {
     return false;
   }
+
   if (token.type === 'Punctuator') {
     const tokenClose = token.value;
     const tokenOpen = decoratorMetaTokens.get(tokenClose);
     if (tokenOpen) {
       let nested = 0;
       let tokenBefore = token;
+      let exitEarlyUnlessTyped = false;
       do {
         tokenBefore = sourceCode.getTokenBefore(tokenBefore, {includeComments: true});
         // istanbul ignore if
         if (tokenBefore && tokenBefore.type === 'Punctuator') {
           if (tokenBefore.value === tokenClose) {
             nested++;
           } else if (tokenBefore.value === tokenOpen) {
+            if (tokenOpen === '(') {
+              exitEarlyUnlessTyped = true;
+            }
             if (nested) {
               nested--;
             } else {
@@ -42,7 +48,33 @@ const getDecorator = (token, sourceCode) => {
         }
       } while (tokenBefore);
 
-      return getDecorator(tokenBefore, sourceCode);
+      // Because our token retrieval doesn't give us as much info as AST, and
+      //  because decorators can be nested and fairly complex, besides finding
+      //  any decorators, we also want to avoid checking backwards indefinitely
+      //  in a potentially large document, so we exit early if parentheses are
+      //  not preceded by a type where we have to keep checking backward for
+      //  now (such as a regular call expression) or if a decorator is found.
+      if (exitEarlyUnlessTyped) {
+        // Check for `@someDecorator(`
+        const identifier = sourceCode.getTokenBefore(tokenBefore, {includeComments: true});
+        if (identifier && identifier.type === 'Identifier') {
+          const before = sourceCode.getTokenBefore(identifier, {includeComments: true});
+          if (before && before.type === 'Punctuator' && before.value === '@') {
+            // Decorator found
+            return before;
+          }
+        }
+
+        // If decorators may have `:`, we might need to check for those as with typed.
+        if (!identifier || identifier.type !== 'Punctuator' || identifier.value !== '>') {
+          // Should not be a decorator
+          return false;
+        }
+
+        // Could be a typed decorator, so keep checking for one
+      }
+
+      return getDecorator(tokenBefore, sourceCode, true);
     }
     if (token.value === '@') {
       return token;

test/rules/assertions/requireJsdoc.js

@@ -2763,6 +2763,35 @@ function quux (foo) {
       `,
       parser: require.resolve('@typescript-eslint/parser'),
     },
+    {
+      code: `
+      @Input()
+      export class UserSettingsState {
+        method () {}
+      }
+      `,
+      errors: [
+        {
+          line: 4,
+          message: 'Missing JSDoc comment.',
+        },
+      ],
+      options: [{
+        require: {
+          MethodDefinition: true,
+        },
+      }],
+      output: `
+      /**
+       *
+       */
+      @Input()
+      export class UserSettingsState {
+        method () {}
+      }
+      `,
+      parser: require.resolve('@typescript-eslint/parser'),
+    },
   ],
   valid: [{
     code: `