CI Speedup: skip optional install steps in tests

.travis.yml

@@ -40,35 +40,50 @@ jobs:
         - npm run ci || exit 1
 
     - stage: test
-      env: WP_VERSION=latest DOCKER=true
+      env:
+        WP_VERSION=latest
+        DOCKER=true
+        SKIP_POSTINSTALL=true
       script:
         - ./bin/run-wp-unit-tests.sh
 
     - stage: test
       php: 5.6
-      env: WP_VERSION=latest
+      env:
+        WP_VERSION=latest
+        SKIP_POSTINSTALL=true
       script:
         - ./bin/run-wp-unit-tests.sh
       if: branch = master and type != "pull_request"
 
     - stage: test
       php: 7.1
-      env: WP_VERSION=latest SWITCH_TO_PHP=5.3
+      env:
+        WP_VERSION=latest
+        SWITCH_TO_PHP=5.3
+        SKIP_POSTINSTALL=true
       script:
         - ./bin/run-wp-unit-tests.sh
       if: branch = master and type != "pull_request"
 
     - stage: test
       php: 7.1
-      env: WP_VERSION=latest SWITCH_TO_PHP=5.2
+      env:
+        WP_VERSION=latest
+        SWITCH_TO_PHP=5.2
+        SKIP_POSTINSTALL=true
       script:
         - ./bin/run-wp-unit-tests.sh
 
     - stage: test
-      env: WP_VERSION=latest
+      env:
+        WP_VERSION=latest
+        SKIP_POSTINSTALL=true
+      cache:
+        yarn: true
       script:
-        - npm install || exit 1
         - ./bin/run-e2e-tests.sh || exit 1
+
     - stage: test
       language: node_js
       node_js: 8
@@ -82,6 +97,7 @@ jobs:
         - cd ./gutenberg-mobile
         - yarn install
         - ./.travis/travis-checks-js.sh
+
     - stage: test
       language: node_js
       node_js: 8
@@ -96,6 +112,7 @@ jobs:
         - cd ./gutenberg-mobile
         - yarn install
         - ./.travis/travis-checks-js.sh
+
     - stage: test
       language: node_js
       node_js: 8

bin/install-docker.sh

@@ -26,7 +26,7 @@ docker-compose $DOCKER_COMPOSE_FILE_OPTIONS down --remove-orphans >/dev/null 2>&
 
 # Download image updates.
 echo -e $(status_message "Downloading Docker image updates...")
-docker-compose $DOCKER_COMPOSE_FILE_OPTIONS pull
+docker-compose $DOCKER_COMPOSE_FILE_OPTIONS pull --parallel
 
 # Launch the containers.
 echo -e $(status_message "Starting Docker containers...")

bin/postinstall.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+if [ "$SKIP_POSTINSTALL" != "true" ]; then
+	npm run mobile-install && npm run check-licenses && npm run build:packages
+fi

package.json

@@ -179,7 +179,7 @@
 		"mobile-submodule-update": "git submodule update --init --recursive",
 		"mobile-install": "yarn --cwd gutenberg-mobile install",
 		"preinstall": "npm run mobile-submodule-update",
-		"postinstall": " npm run mobile-install && npm run check-licenses && npm run build:packages",
+		"postinstall": "./bin/postinstall.sh",
 		"pot-to-php": "./bin/pot-to-php.js",
 		"precommit": "lint-staged",
 		"publish:check": "npm run build:packages && lerna updated",