From 604856b2f196bca16cb2c336829586a8b93dee4d Mon Sep 17 00:00:00 2001
From: Russell Bicknell <bicknellr@google.com>
Date: Tue, 28 Apr 2020 14:59:11 -0700
Subject: [PATCH] Update Closure types for overridden setAttribute in
 LegacyElementMixin.

---
 gen-tsd.json                       | 3 ++-
 lib/legacy/legacy-element-mixin.js | 8 +++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/gen-tsd.json b/gen-tsd.json
index abb67b6cab..475d21b2cf 100644
--- a/gen-tsd.json
+++ b/gen-tsd.json
@@ -8,7 +8,8 @@
     "index.html"
   ],
   "excludeIdentifiers": [
-    "templatizedBase"
+    "templatizedBase",
+    "setAttribute"
   ],
   "removeReferences": [
     "../shadycss/apply-shim.d.ts",
diff --git a/lib/legacy/legacy-element-mixin.js b/lib/legacy/legacy-element-mixin.js
index cfa17c6f0d..c443ca7ef8 100644
--- a/lib/legacy/legacy-element-mixin.js
+++ b/lib/legacy/legacy-element-mixin.js
@@ -145,9 +145,15 @@ export const LegacyElementMixin = dedupingMixin((base) => {
 
     /**
      * Sets the value of an attribute.
+     *
+     * NOTE: This function is explicitly excluded when running
+     * gen-typescript-declarations because the function it overrides has
+     * different signatures in Closure and TypeScript's built-in types. This
+     * function's signature should match the signature from Closure:
+     * https://github.com/google/closure-compiler/blob/8972fd4e9b0689e7ebdeea53580521c819f6aecc/externs/browser/w3c_dom1.js#L686-L694
      * @override
      * @param {string} name The name of the attribute to change.
-     * @param {string} value The new attribute value.
+     * @param {string|number|boolean|!TrustedHTML|!TrustedScriptURL|!TrustedURL} value The new attribute value.
      */
     setAttribute(name, value) {
       if (legacyNoObservedAttributes && !this._legacyForceObservedAttributes) {