Support nestled JSDoc comments

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 "../../print/comment.js";
 import visitNode from "./visit-node.js";
 import { throwErrorForInvalidNodes } from "./typescript.js";
 import throwSyntaxError from "./throw-ts-syntax-error.js";
@@ -154,6 +157,29 @@ function postprocess(ast, options) {
     }
   });
 
+  /* eslint-disable prettier-internal-rules/no-node-comments */
+  if (isNonEmptyArray(ast.comments)) {
+    for (let i = ast.comments.length - 2; i >= 0; i--) {
+      const comment = ast.comments[i];
+      const nextComment = ast.comments[i + 1];
+      if (
+        isBlockComment(comment) &&
+        isIndentableBlockComment(comment) &&
+        isBlockComment(nextComment) &&
+        isIndentableBlockComment(nextComment) &&
+        locEnd(comment) === locStart(nextComment)
+      ) {
+        ast.comments.splice(i + 1, 1);
+        ast.comments[i] = {
+          ...comment,
+          value: comment.value + "*//*" + nextComment.value,
+          range: [locStart(comment), locEnd(nextComment)],
+        };
+      }
+    }
+  }
+  /* eslint-enable prettier-internal-rules/no-node-comments */
+
   return ast;
 
   /**

src/language-js/print/comment.js

@@ -60,4 +60,4 @@ function printIndentableBlockComment(comment) {
   ];
 }
 
-export { printComment };
+export { printComment, isIndentableBlockComment };

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

@@ -3144,6 +3144,226 @@ 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
+ */
+
+=====================================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
+ */
+
+================================================================================
+`;
+
+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
+ */
+
+=====================================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
+ */
+
+================================================================================
+`;
+
+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"]