From b346f5764e4d500ebdeff7086e43690ea533a305 Mon Sep 17 00:00:00 2001
From: sergeir82 <sergeir82@gmail.com>
Date: Fri, 17 Apr 2020 23:18:05 +0300
Subject: [PATCH] prefix-unused-parameter-with-_ codefix now works in jsdoc
 @param (#36152)

* Fix prepending unused TypeScript variables with underscore doesn't rename JSDoc @param.
Fix test for quick fix "Prefix all unused declarations with '_' where possible".
Fixes #33021.

* Replace FindAllReferences.Core.eachSymbolReferenceInFile function call to more ligher call of getJSDocParameterTags when searching for a parameter in jsdoc.

* Remove redundant constant declaration.

* Add test for prefix single unused parameter in jsdoc.
---
 src/services/codefixes/fixUnusedIdentifier.ts |  7 ++++++
 .../codeFixUnusedIdentifier_all_prefix.ts     | 10 +++++++-
 .../codeFixUnusedIdentifier_prefix.ts         | 25 +++++++++++++++++++
 3 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/codeFixUnusedIdentifier_prefix.ts

diff --git a/src/services/codefixes/fixUnusedIdentifier.ts b/src/services/codefixes/fixUnusedIdentifier.ts
index 8439c1e8fc3..7644c8df269 100644
--- a/src/services/codefixes/fixUnusedIdentifier.ts
+++ b/src/services/codefixes/fixUnusedIdentifier.ts
@@ -154,6 +154,13 @@ namespace ts.codefix {
         }
         if (isIdentifier(token) && canPrefix(token)) {
             changes.replaceNode(sourceFile, token, createIdentifier(`_${token.text}`));
+            if (isParameter(token.parent)) {
+                getJSDocParameterTags(token.parent).forEach((tag) => {
+                    if (isIdentifier(tag.name)) {
+                        changes.replaceNode(sourceFile, tag.name, createIdentifier(`_${tag.name.text}`));
+                    }
+                });
+            }
         }
     }
 
diff --git a/tests/cases/fourslash/codeFixUnusedIdentifier_all_prefix.ts b/tests/cases/fourslash/codeFixUnusedIdentifier_all_prefix.ts
index f77fef6510f..4eb7137d365 100644
--- a/tests/cases/fourslash/codeFixUnusedIdentifier_all_prefix.ts
+++ b/tests/cases/fourslash/codeFixUnusedIdentifier_all_prefix.ts
@@ -3,6 +3,10 @@
 // @noUnusedLocals: true
 // @noUnusedParameters: true
 
+/////**
+//// * @param a First parameter.
+//// * @param b Second parameter.
+//// */ 
 ////function f(a, b) {
 ////    const x = 0; // Can't be prefixed, ignored
 ////}
@@ -12,7 +16,11 @@ verify.codeFixAll({
     fixId: "unusedIdentifier_prefix",
     fixAllDescription: "Prefix all unused declarations with '_' where possible",
     newFileContent:
-`function f(_a, _b) {
+`/**
+ * @param _a First parameter.
+ * @param _b Second parameter.
+ */ 
+function f(_a, _b) {
     const x = 0; // Can't be prefixed, ignored
 }
 type Length<T> = T extends ArrayLike<infer _U> ? number : never;`,
diff --git a/tests/cases/fourslash/codeFixUnusedIdentifier_prefix.ts b/tests/cases/fourslash/codeFixUnusedIdentifier_prefix.ts
new file mode 100644
index 00000000000..80b2b9bb75c
--- /dev/null
+++ b/tests/cases/fourslash/codeFixUnusedIdentifier_prefix.ts
@@ -0,0 +1,25 @@
+/// <reference path='fourslash.ts' />
+
+// @noUnusedLocals: true
+// @noUnusedParameters: true
+
+/////**
+//// * @param a
+//// * @param b
+//// */
+////function f(a, b) {
+////    const x = a;
+////}
+
+verify.codeFix({
+    description: "Prefix 'b' with an underscore",
+    index: 1,
+    newFileContent:
+`/**
+ * @param a
+ * @param _b
+ */
+function f(a, _b) {
+    const x = a;
+}`,
+});