chore: Upgrade compiler

The latest compiler should treat `@expose` as a parser error, so the
BanExpose conformance rule is no longer needed.

This upgrades the compiler & closure libraries to the latest releases
from NPM, makes matching updates to the compiler command line (no more
`strictMissingRequire` error category), and removes the BanExpose
conformance rule.

Change-Id: I45e8e71ad5f42fee289a8ddd30141e15f3f425a8

build/apps.py

@@ -74,7 +74,7 @@ def compile_demo(force, is_debug):
   closure_opts += [
       # Ignore missing goog.require since we assume the whole library is
       # already included.
-      '--jscomp_off=missingRequire', '--jscomp_off=strictMissingRequire',
+      '--jscomp_off=missingRequire',
       '-D', 'COMPILED=true',
   ]
 
@@ -125,7 +125,7 @@ def compile_receiver(force, is_debug):
   closure_opts += [
       # Ignore missing goog.require since we assume the whole library is
       # already included.
-      '--jscomp_off=missingRequire', '--jscomp_off=strictMissingRequire',
+      '--jscomp_off=missingRequire',
       '-D', 'COMPILED=true',
   ]
 

build/check.py

@@ -295,8 +295,8 @@ def check_tests(args):
   # Ignore missing goog.require since we assume the whole library is
   # already included.
   closure_opts += [
-      '--jscomp_off=missingRequire', '--jscomp_off=strictMissingRequire',
-      '--checks-only', '-O', 'SIMPLE'
+      '--jscomp_off=missingRequire',
+      '--checks-only', '-O', 'SIMPLE',
   ]
 
   # Set up a build with the build name of "dummy".  With output_compiled_bundle

build/conformance.textproto

@@ -58,15 +58,6 @@ requirement {
 }
 
 
-# Ban the use of @expose annotations.
-requirement {
-  type: CUSTOM
-  java_class: 'com.google.javascript.jscomp.ConformanceRules$BanExpose'
-  error_message: '@expose is not allowed; please use externs instead. '
-                 'See docs/design/export.md for details.'
-}
-
-
 # Reject unresolved types.
 requirement {
   type: CUSTOM

package.json

@@ -28,8 +28,8 @@
     "esprima": "^4.0.1",
     "fastestsmallesttextencoderdecoder": "^1.0.22",
     "fontfaceonload": "^1.0.2",
-    "google-closure-compiler-java": "^20201006.0.0",
-    "google-closure-library": "^20200830.0.0",
+    "google-closure-compiler-java": "^20210505.0.0",
+    "google-closure-library": "^20210406.0.0",
     "htmlhint": "^0.11.0",
     "jasmine-ajax": "^4.0.0",
     "jimp": "^0.11.0",