Move test scenario for creating block to shell script

.github/workflows/create-block.yml

@@ -20,14 +20,9 @@ jobs:
       uses: actions/setup-node@v1
       with:
         node-version: 12.x
-    - name: npm install, build, and test
+    - name: npm install, build, format and lint
       run: |
         npm ci
-        npx wp-create-block esnext-test --no-wp-scripts
-        cd esnext-test
-        ../node_modules/.bin/wp-scripts format-js
-        ../node_modules/.bin/wp-scripts build
-        ../node_modules/.bin/wp-scripts lint-style
-        ../node_modules/.bin/wp-scripts lint-js
+        npm run test:create-block
       env:
         CI: true

bin/test-create-block.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+# This script validates whether `npm init @wordpress/block` works properly
+# with the latest changes applied to the `master` branch. It purpousfuly
+# avoids installing `@wordpress/scripts` package from npm when scaffolding
+# a test block and uses the local package by executing everything from the
+# root of the project.
+
+# Exit if any command fails.
+set -e
+
+status () {
+	echo -e "\n\033[1;34m$1\033[0m\n"
+}
+
+status "Scaffolding block..."
+rm -rf esnext-test
+npx wp-create-block esnext-test --no-wp-scripts
+cd esnext-test
+
+status "Formatting JavaScript files..."
+../node_modules/.bin/wp-scripts format-js
+
+status "Building block..."
+../node_modules/.bin/wp-scripts build
+
+status "Lintig CSS files..."
+../node_modules/.bin/wp-scripts lint-style
+
+status "Linting JavaScript files..."
+../node_modules/.bin/wp-scripts lint-js

package.json

@@ -227,6 +227,7 @@
 		"publish:patch": "npm run clean:package-types && npm run build:packages && lerna publish --dist-tag patch",
 		"publish:prod": "npm run clean:package-types && npm run build:packages && lerna publish",
 		"test": "npm run lint && npm run test-unit",
+		"test:create-block": "./bin/test-create-block.sh",
 		"test-e2e": "wp-scripts test-e2e --config packages/e2e-tests/jest.config.js",
 		"test-e2e:debug": "wp-scripts --inspect-brk test-e2e --config packages/e2e-tests/jest.config.js --puppeteer-devtools",
 		"test-e2e:watch": "npm run test-e2e -- --watch",