Downport "Simplify installing / running polylint"

Install it locally (to avoid version clashes) and then run it with npx (which
finds the locally installed package even when it's not on the path).

Change-Id: Ib0a6a57d373ada0b22d2030053ac696845059bc6

package.json

@@ -8,6 +8,7 @@
     "eslint-config-google": "^0.13.0",
     "eslint-plugin-html": "^5.0.5",
     "fried-twinkie": "^0.2.2",
+    "polylint": "^2.10.4",
     "typescript": "^2.x.x",
     "web-component-tester": "^6.5.0"
   },
@@ -15,7 +16,8 @@
     "start": "polygerrit-ui/run-server.sh",
     "test": "WCT_HEADLESS_MODE=1 WCT_ARGS='--verbose -l chrome' ./polygerrit-ui/app/run_test.sh",
     "eslint": "./node_modules/eslint/bin/eslint.js --ignore-pattern 'bower_components/' --ignore-pattern 'gr-linked-text' --ignore-pattern 'scripts/vendor' --ext .html,.js polygerrit-ui/app || exit 0",
-    "test-template": "./polygerrit-ui/app/run_template_test.sh"
+    "test-template": "./polygerrit-ui/app/run_template_test.sh",
+    "polylint": "bazel test polygerrit-ui/app:polylint_test"
   },
   "repository": {
     "type": "git",

polygerrit-ui/README.md

@@ -28,7 +28,6 @@ dependencies can be installed with:
 
 ```sh
 npm install
-sudo npm install -g polylint
 ```
 
 It may complain about a missing `typescript@2.3.4` peer dependency, which is
@@ -173,6 +172,13 @@ To run polylint, execute the following command.
 ```sh
 bazel test //polygerrit-ui/app:polylint_test
 ```
+
+or
+
+```sh
+npm run polylint
+```
+
 ## Template Type Safety
 Polymer elements are not type checked against the element definition, making it trivial to break the display when refactoring or moving code. We now run additional tests to help ensure that template types are checked.
 

polygerrit-ui/app/polylint_test.sh

@@ -8,13 +8,13 @@ if [[ -z "$npm_bin" ]]; then
     exit 1
 fi
 
-polylint_bin=$(which polylint)
-if [[ -z "$polylint_bin" ]]; then
-    echo "You must install polylint and its dependencies from NPM."
-    echo "> npm install -g polylint"
+npx_bin=$(which npx)
+if [[ -z "$npx_bin" ]]; then
+    echo "NPX must be on the path."
+    echo "> npm i -g npx"
     exit 1
 fi
 
 unzip -o polygerrit-ui/polygerrit_components.bower_components.zip -d polygerrit-ui/app
 
-${polylint_bin} --root polygerrit-ui/app --input elements/gr-app.html --b 'bower_components'
+npx polylint --root polygerrit-ui/app --input elements/gr-app.html --b 'bower_components' --verbose