Add 'no-redundant-jsdoc' rule (#2754)

src/configs/all.ts

@@ -198,6 +198,7 @@ export const rules = {
     "no-boolean-literal-compare": true,
     "no-consecutive-blank-lines": true,
     "no-parameter-properties": true,
+    "no-redundant-jsdoc": true,
     "no-reference-import": true,
     "no-unnecessary-callback-wrapper": true,
     "no-unnecessary-initializer": true,

src/language/formatter/formatter.ts

@@ -53,8 +53,8 @@ export interface FormatterConstructor {
 export interface IFormatter {
     /**
      * Formats linter results
-     * @param {RuleFailure[]} failures Linter failures that were not fixed
-     * @param {RuleFailure[]} fixes Fixed linter failures. Available when the `--fix` argument is used on the command line
+     * @param failures Linter failures that were not fixed
+     * @param fixes Fixed linter failures. Available when the `--fix` argument is used on the command line
      */
     format(failures: RuleFailure[], fixes?: RuleFailure[]): string;
 }

src/rules/noRedundantJsdocRule.ts

@@ -0,0 +1,132 @@
+/**
+ * @license
+ * Copyright 2017 Palantir Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { getJsDoc } from "tsutils";
+import * as ts from "typescript";
+
+import * as Lint from "../index";
+
+export class Rule extends Lint.Rules.AbstractRule {
+    /* tslint:disable:object-literal-sort-keys */
+    public static metadata: Lint.IRuleMetadata = {
+        ruleName: "no-redundant-jsdoc",
+        description: "Forbids JSDoc which duplicates TypeScript functionality.",
+        optionsDescription: "Not configurable.",
+        options: null,
+        optionExamples: [true],
+        type: "style",
+        typescriptOnly: true,
+    };
+    /* tslint:enable:object-literal-sort-keys */
+
+    public static FAILURE_STRING_REDUNDANT_TYPE =
+        "Type annotation in JSDoc is redundant in TypeScript code.";
+    public static FAILURE_STRING_REDUNDANT_TAG(tagName: string): string {
+        return `JSDoc tag '@${tagName}' is redundant in TypeScript code.`;
+    }
+    public static FAILURE_STRING_NO_COMMENT(tagName: string): string {
+        return `'@${tagName}' is redundant in TypeScript code if it has no description.`;
+    }
+
+    public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
+        return this.applyWithFunction(sourceFile, walk);
+    }
+}
+
+function walk(ctx: Lint.WalkContext<void>): void {
+    const { sourceFile } = ctx;
+    ts.forEachChild(sourceFile, function cb(node) {
+        for (const { tags } of getJsDoc(node, sourceFile)) {
+            if (tags !== undefined) {
+                for (const tag of tags) {
+                    checkTag(tag);
+                }
+            }
+        }
+        ts.forEachChild(node, cb);
+    });
+
+    function checkTag(tag: ts.JSDocTag): void {
+        switch (tag.kind) {
+            case ts.SyntaxKind.JSDocTag:
+                if (redundantTags.has(tag.tagName.text)) {
+                    ctx.addFailureAtNode(tag.tagName, Rule.FAILURE_STRING_REDUNDANT_TAG(tag.tagName.text));
+                }
+                break;
+
+            case ts.SyntaxKind.JSDocAugmentsTag:
+                // OK
+                break;
+
+            case ts.SyntaxKind.JSDocTemplateTag:
+            case ts.SyntaxKind.JSDocTypeTag:
+            case ts.SyntaxKind.JSDocTypedefTag:
+            case ts.SyntaxKind.JSDocPropertyTag:
+                // Always redundant
+                ctx.addFailureAtNode(tag.tagName, Rule.FAILURE_STRING_REDUNDANT_TAG(tag.tagName.text));
+                break;
+
+            case ts.SyntaxKind.JSDocReturnTag:
+            case ts.SyntaxKind.JSDocParameterTag: {
+                const { typeExpression, comment } = tag as ts.JSDocReturnTag | ts.JSDocParameterTag;
+                if (typeExpression !== undefined) {
+                    ctx.addFailureAtNode(typeExpression, Rule.FAILURE_STRING_REDUNDANT_TYPE);
+                }
+                if (comment === "") {
+                    // Redundant if no documentation
+                    ctx.addFailureAtNode(tag.tagName, Rule.FAILURE_STRING_NO_COMMENT(tag.tagName.text));
+                }
+                break;
+            }
+
+            default:
+                throw new Error(`Unexpected tag kind: ${ts.SyntaxKind[tag.kind]}`);
+        }
+    }
+}
+
+const redundantTags = new Set([
+    "abstract",
+    "access",
+    "class",
+    "constant",
+    "constructs",
+    "default",
+    "enum",
+    "exports",
+    "function",
+    "global",
+    "implements",
+    "interface",
+    "instance",
+    "member",
+    "memberof",
+    "mixes",
+    "mixin",
+    "module",
+    "name",
+    "namespace",
+    "override",
+    "private",
+    "property",
+    "protected",
+    "public",
+    "readonly",
+    "requires",
+    "static",
+    "this",
+]);

test/rules/no-redundant-jsdoc/test.ts.lint

@@ -0,0 +1,35 @@
+/** @typedef {number} T */
+     ~~~~~~~ [tag % ('typedef')]
+
+/** @function */
+     ~~~~~~~~ [tag % ('function')]
+function f() {}
+
+/** @type number */
+     ~~~~ [tag % ('type')]
+const x = 0;
+
+/**
+ * @param {number} x Is a number
+          ~~~~~~~~ [type]
+ * @param y
+    ~~~~~ [param]
+ * @param {number} z
+    ~~~~~ [param]
+          ~~~~~~~~ [type]
+ * @returns {number}
+    ~~~~~~~ [returns]
+            ~~~~~~~~ [type]
+ */
+declare function g(x: number, y: number, z: number): number;
+
+/**
+ * @param x Useful comment
+ * @returns Useful comment
+ */
+declare function h(x: number): number;
+
+[tag]: JSDoc tag '@%s' is redundant in TypeScript code.
+[type]: Type annotation in JSDoc is redundant in TypeScript code.
+[param]: '@param' is redundant in TypeScript code if it has no description.
+[returns]: '@returns' is redundant in TypeScript code if it has no description.

test/rules/no-redundant-jsdoc/tslint.json

@@ -0,0 +1,5 @@
+{
+  "rules": {
+    "no-redundant-jsdoc": true
+  }
+}

yarn.lock

@@ -1591,8 +1591,8 @@ tsutils@^2.12.1:
     tslib "^1.7.1"
 
 tsutils@^2.8.1:
-  version "2.8.1"
-  resolved "https://registry.yarnpkg.com/tsutils/-/tsutils-2.8.1.tgz#3771404e7ca9f0bedf5d919a47a4b1890a68efff"
+  version "2.10.0"
+  resolved "https://registry.yarnpkg.com/tsutils/-/tsutils-2.10.0.tgz#ae94511df2656eb06e4424056fba5c388887040c"
   dependencies:
     tslib "^1.7.1"