test: make integration test more reliable (#14413)

Use a fresh yarn cache
tsickle bugfix to write case-sensitive filenames for Mac

integration/run_tests.sh

@@ -16,6 +16,16 @@ if [ ! -d "../dist/packages-dist-es2015" ]; then
   exit 1
 fi
 
+# Workaround https://github.com/yarnpkg/yarn/issues/2165
+# Yarn will cache file://dist URIs and not update Angular code
+readonly cache=.yarn_local_cache
+function rm_cache {
+  rm -rf $cache
+}
+rm_cache
+mkdir $cache
+trap rm_cache EXIT
+
 for testDir in $(ls | grep -v rxjs | grep -v node_modules) ; do
   [[ -d "$testDir" ]] || continue
   echo "#################################"
@@ -25,7 +35,7 @@ for testDir in $(ls | grep -v rxjs | grep -v node_modules) ; do
     cd $testDir
     # Workaround for https://github.com/yarnpkg/yarn/issues/2256
     rm -f yarn.lock
-    yarn
+    yarn install --cache-folder ../$cache
     yarn test || exit 1
   )
 done