Support nestled JSDoc comments (prettier#13445)

.eslintrc.cjs

@@ -322,6 +322,7 @@ module.exports = {
     },
     {
       files: ["src/language-js/**/*.js"],
+      excludedFiles: ["src/language-js/parse/postprocess/*.js"],
       rules: {
         "prettier-internal-rules/no-node-comments": [
           "error",
@@ -330,7 +331,6 @@ module.exports = {
             functions: ["hasComment", "getComments"],
           },
           "src/language-js/pragma.js",
-          "src/language-js/parse/postprocess/*.js",
           "src/language-js/parse/babel.js",
           "src/language-js/parse/meriyah.js",
           "src/language-js/parse/json.js",

changelog_unreleased/javascript/13445.md

@@ -0,0 +1,60 @@
+#### Support nestled JSDoc comments (#13445 by @thorn0)
+
+This kind of comments is used to document overloaded functions (see https://github.com/jsdoc/jsdoc/issues/1017).
+
+<!-- prettier-ignore -->
+```jsx
+// Input
+/**
+ * @template T
+ * @param {Type} type
+ * @param {T} value
+ * @return {Value}
+ *//**
+ * @param {Type} type
+ * @return {Value}
+ */
+function value(type, value) {
+  if (arguments.length === 2) {
+    return new ConcreteValue(type, value);
+  } else {
+    return new Value(type);
+  }
+}
+
+// Prettier stable
+/**
+ * @template T
+ * @param {Type} type
+ * @param {T} value
+ * @return {Value}
+ */ /**
+ * @param {Type} type
+ * @return {Value}
+ */
+function value(type, value) {
+  if (arguments.length === 2) {
+    return new ConcreteValue(type, value);
+  } else {
+    return new Value(type);
+  }
+}
+
+// Prettier main
+/**
+ * @template T
+ * @param {Type} type
+ * @param {T} value
+ * @return {Value}
+ *//**
+ * @param {Type} type
+ * @return {Value}
+ */
+function value(type, value) {
+  if (arguments.length === 2) {
+    return new ConcreteValue(type, value);
+  } else {
+    return new Value(type);
+  }
+}
+```

src/language-js/parse/postprocess/index.js

@@ -2,6 +2,9 @@ import { locStart, locEnd } from "../../loc.js";
 import isTsKeywordType from "../../utils/is-ts-keyword-type.js";
 import isTypeCastComment from "../../utils/is-type-cast-comment.js";
 import getLast from "../../../utils/get-last.js";
+import isNonEmptyArray from "../../../utils/is-non-empty-array.js";
+import isBlockComment from "../../utils/is-block-comment.js";
+import isIndentableBlockComment from "../../utils/is-indentable-block-comment.js";
 import visitNode from "./visit-node.js";
 import throwSyntaxError from "./throw-ts-syntax-error.js";
 
@@ -165,6 +168,25 @@ function postprocess(ast, options) {
     }
   });
 
+  if (isNonEmptyArray(ast.comments)) {
+    let followingComment = getLast(ast.comments);
+    for (let i = ast.comments.length - 2; i >= 0; i--) {
+      const comment = ast.comments[i];
+      if (
+        locEnd(comment) === locStart(followingComment) &&
+        isBlockComment(comment) &&
+        isBlockComment(followingComment) &&
+        isIndentableBlockComment(comment) &&
+        isIndentableBlockComment(followingComment)
+      ) {
+        ast.comments.splice(i + 1, 1);
+        comment.value += "*//*" + followingComment.value;
+        comment.range = [locStart(comment), locEnd(followingComment)];
+      }
+      followingComment = comment;
+    }
+  }
+
   return ast;
 
   /**

src/language-js/print/comment.js

@@ -4,6 +4,7 @@ import { replaceEndOfLine } from "../../document/utils.js";
 import { isLineComment } from "../utils/index.js";
 import { locStart, locEnd } from "../loc.js";
 import isBlockComment from "../utils/is-block-comment.js";
+import isIndentableBlockComment from "../utils/is-indentable-block-comment.js";
 
 function printComment(commentPath, options) {
   const comment = commentPath.node;
@@ -34,15 +35,6 @@ function printComment(commentPath, options) {
   throw new Error("Not a comment: " + JSON.stringify(comment));
 }
 
-function isIndentableBlockComment(comment) {
-  // If the comment has multiple lines and every line starts with a star
-  // we can fix the indentation of each line. The stars in the `/*` and
-  // `*/` delimiters are not included in the comment value, so add them
-  // back first.
-  const lines = `*${comment.value}*`.split("\n");
-  return lines.length > 1 && lines.every((line) => line.trim()[0] === "*");
-}
-
 function printIndentableBlockComment(comment) {
   const lines = comment.value.split("\n");
 
@@ -60,4 +52,4 @@ function printIndentableBlockComment(comment) {
   ];
 }
 
-export { printComment };
+export { printComment, isIndentableBlockComment };

src/language-js/utils/is-indentable-block-comment.js

@@ -0,0 +1,10 @@
+function isIndentableBlockComment(comment) {
+  // If the comment has multiple lines and every line starts with a star
+  // we can fix the indentation of each line. The stars in the `/*` and
+  // `*/` delimiters are not included in the comment value, so add them
+  // back first.
+  const lines = `*${comment.value}*`.split("\n");
+  return lines.length > 1 && lines.every((line) => line.trimStart()[0] === "*");
+}
+
+export default isIndentableBlockComment;

tests/format/js/comments/__snapshots__/jsfmt.spec.js.snap

@@ -3134,6 +3134,230 @@ function HelloWorld() {
 ================================================================================
 `;
 
+exports[`jsdoc-nestled.js - {"semi":false} format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+const issues = {
+  see: "#7724 and #12653"
+  /** Trailing comment 1 (not nestled as both comments should be multiline for that) *//**
+  * Trailing comment 2
+  */
+};
+
+/**
+ * @template T
+ * @param {Type} type
+ * @param {T} value
+ * @return {Value}
+ *//**
+ * @param {Type} type
+ * @return {Value}
+ */
+function value(type, value) {
+  if (arguments.length === 2) {
+    return new ConcreteValue(type, value);
+  } else {
+    return new Value(type);
+  }
+}
+
+/** Trailing nestled comment 1
+ *//** Trailing nestled comment 2
+ *//** Trailing nestled comment 3
+ */
+
+=====================================output=====================================
+const issues = {
+  see: "#7724 and #12653",
+  /** Trailing comment 1 (not nestled as both comments should be multiline for that) */ /**
+   * Trailing comment 2
+   */
+}
+
+/**
+ * @template T
+ * @param {Type} type
+ * @param {T} value
+ * @return {Value}
+ *//**
+ * @param {Type} type
+ * @return {Value}
+ */
+function value(type, value) {
+  if (arguments.length === 2) {
+    return new ConcreteValue(type, value)
+  } else {
+    return new Value(type)
+  }
+}
+
+/** Trailing nestled comment 1
+ *//** Trailing nestled comment 2
+ *//** Trailing nestled comment 3
+ */
+
+================================================================================
+`;
+
+exports[`jsdoc-nestled.js format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+const issues = {
+  see: "#7724 and #12653"
+  /** Trailing comment 1 (not nestled as both comments should be multiline for that) *//**
+  * Trailing comment 2
+  */
+};
+
+/**
+ * @template T
+ * @param {Type} type
+ * @param {T} value
+ * @return {Value}
+ *//**
+ * @param {Type} type
+ * @return {Value}
+ */
+function value(type, value) {
+  if (arguments.length === 2) {
+    return new ConcreteValue(type, value);
+  } else {
+    return new Value(type);
+  }
+}
+
+/** Trailing nestled comment 1
+ *//** Trailing nestled comment 2
+ *//** Trailing nestled comment 3
+ */
+
+=====================================output=====================================
+const issues = {
+  see: "#7724 and #12653",
+  /** Trailing comment 1 (not nestled as both comments should be multiline for that) */ /**
+   * Trailing comment 2
+   */
+};
+
+/**
+ * @template T
+ * @param {Type} type
+ * @param {T} value
+ * @return {Value}
+ *//**
+ * @param {Type} type
+ * @return {Value}
+ */
+function value(type, value) {
+  if (arguments.length === 2) {
+    return new ConcreteValue(type, value);
+  } else {
+    return new Value(type);
+  }
+}
+
+/** Trailing nestled comment 1
+ *//** Trailing nestled comment 2
+ *//** Trailing nestled comment 3
+ */
+
+================================================================================
+`;
+
+exports[`jsdoc-nestled-dangling.js - {"semi":false} format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+{{{{{{{
+o={
+  /**
+   * A
+   *//**
+   * B
+   */
+
+}
+}}}}}}}
+
+=====================================output=====================================
+{
+  {
+    {
+      {
+        {
+          {
+            {
+              o = {
+                /**
+                 * A
+                 *//**
+                 * B
+                 */
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
+
+================================================================================
+`;
+
+exports[`jsdoc-nestled-dangling.js format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+{{{{{{{
+o={
+  /**
+   * A
+   *//**
+   * B
+   */
+
+}
+}}}}}}}
+
+=====================================output=====================================
+{
+  {
+    {
+      {
+        {
+          {
+            {
+              o = {
+                /**
+                 * A
+                 *//**
+                 * B
+                 */
+              };
+            }
+          }
+        }
+      }
+    }
+  }
+}
+
+================================================================================
+`;
+
 exports[`jsx.js - {"semi":false} format 1`] = `
 ====================================options=====================================
 parsers: ["babel", "flow", "typescript"]

tests/format/js/comments/jsdoc-nestled-dangling.js

@@ -0,0 +1,10 @@
+{{{{{{{
+o={
+  /**
+   * A
+   *//**
+   * B
+   */
+
+}
+}}}}}}}