Upgrade to Backstop 3.x and Chrome Headless. Fixes #4

- Switched to node:8.5.0-alpine (Alpine 3.6)
- Using the latest Chromium version from alpine/edge (Chromy requires Chrome ver.61 or later)
- Cleaned up SlimerJS dependencies
- Using GNU grep for compatibility (busybox grep uses -r vs -R)
- Setting NPM_CONFIG_UNSAFE_PERM=true for compatibility between phantomjs-prebuilt and recent nodejs/npm versions
- Added basic bats tests
- Updated README

.travis.yml

@@ -0,0 +1,12 @@
+language: generic
+
+services:
+  - docker
+
+install:
+  - curl -fsSL get.docksal.io | sh
+  - fin version
+  - fin sysinfo
+
+script:
+  - make && make test

Dockerfile

@@ -1,26 +1,23 @@
-FROM mhart/alpine-node:6.10.0
+FROM node:8.5.0-alpine
 
+ENV \
+	PHANTOMJS_VERSION=2.1.1 \
+	CASPERJS_VERSION=1.1.4 \
+	SLIMERJS_VERSION=0.10.3 \
+	BACKSTOPJS_VERSION=3.0.25 \
+	# Workaround to fix phantomjs-prebuilt installation errors
+	# See https://github.com/Medium/phantomjs/issues/707
+	NPM_CONFIG_UNSAFE_PERM=true
+
+# Base packages
 RUN apk add --no-cache \
 	bash \
-	coreutils \
 	curl \
-	git \
 	python \
-	dbus \
-	firefox-esr \
-	fontconfig \
-	ttf-freefont \
-	xvfb
+	# Use GNU grep to avoid compatibility issues (busybox grep uses -r vs -R)
+	grep
 
-# xvfb wrapper
-COPY xvfb-run /usr/bin/xvfb-run
-
-ENV PHANTOMJS_VERSION 2.1.1
-ENV CASPERJS_VERSION 1.1.4
-ENV SLIMERJS_VERSION 0.10.3
-ENV BACKSTOPJS_VERSION 2.6.9
-
-# Installing dependencies from archives - not only this allows us to control versions, 
+# Installing dependencies from archives - not only this allows us to control versions,
 # but the resulting image size is 130MB+ less (!) compared to an npm install (440MB vs 575MB).
 RUN \
 	mkdir -p /opt && \
@@ -55,6 +52,28 @@ RUN \
 	echo "Installing BackstopJS v${BACKSTOPJS_VERSION}..." && \
 	npm install -g backstopjs@${BACKSTOPJS_VERSION}
 
+ENV \
+	CHROMIUM_VERSION=61.0 \
+	FIREFOX_VERSION=52.3 \
+	CHROME_PATH=/usr/bin/chromium-browser
+
+# Chrome (from edge)
+RUN apk add --no-cache --repository http://dl-cdn.alpinelinux.org/alpine/edge/main --repository http://dl-cdn.alpinelinux.org/alpine/edge/community \
+	"chromium>${CHROMIUM_VERSION}"
+
+# Firefox (from edge)
+RUN apk add --no-cache \
+	"firefox-esr>${FIREFOX_VERSION}"
+
+# SlimerJS dependencies
+RUN \
+	apk add --no-cache \
+	dbus \
+	xvfb
+
+# xvfb wrapper
+COPY xvfb-run /usr/bin/xvfb-run
+
 WORKDIR /src
 
 ENTRYPOINT ["backstop"]

Makefile

@@ -0,0 +1,22 @@
+-include env_make
+
+VERSION ?= 3
+
+REPO = docksal/backstopjs
+NAME = docksal-backstopjs-$(VERSION)
+
+.PHONY: build test push shell run start stop logs clean release
+
+build:
+	fin docker build -t $(REPO):$(VERSION) .
+
+test:
+	IMAGE=$(REPO):$(VERSION) NAME=$(NAME) tests/test.bats
+
+shell:
+	fin docker run --rm --name $(NAME) -it $(PORTS) $(VOLUMES) $(ENV) --entrypoint=bash $(REPO):$(VERSION)
+
+clean:
+	fin docker rm -f $(NAME) || true
+
+default: build

README.md

@@ -2,12 +2,21 @@
 
 A self-contained Docker image to run [BackstopJS](https://github.com/garris/BackstopJS) with no external dependencies.
 
+[Visual Regression Testing with BackstopJS in a Docker container](https://blog.docksal.io/visual-regression-testing-with-backstopjs-in-a-docker-container-dfd1b9ae8582)
+
 Features:
 
-- [BackstopJS 2.x](https://github.com/garris/BackstopJS)
-- [PhantomJS](http://phantomjs.org/), 
-- [SlimerJS](https://slimerjs.org/) (with Firefox ESR), 
+- [BackstopJS 3.x](https://github.com/garris/BackstopJS)
+- [PhantomJS](http://phantomjs.org/)
+- [SlimerJS](https://slimerjs.org/) (with Firefox ESR)
 - [CasperJS](http://casperjs.org/)
+- Chromium
+
+
+## Versions
+
+- `docksal/backstopjs:2` - BackstopJS 2.x (legacy)
+- `docksal/backstopjs` (`docksal/backstopjs:3`) - BackstopJS 3 with Chrome Headless support
 
 
 ## Usage
@@ -17,7 +26,7 @@ Working directory is expected to be mounted at `/src` in the container.
 
 ```
 $ docker run --rm -v $(pwd):/src docksal/backstopjs --version
-BackstopJS 2.0.2
+BackstopJS v3.0.25
 ```
 
 You can also add a shell alias (in `.bashrc`, `.zshrc`, etc.) for convenience.
@@ -30,38 +39,42 @@ Restart your shell or open a new one, then
 
 ```
 $ backstopjs --version
-BackstopJS 2.0.2
+BackstopJS v3.0.25
 ```
 
 
 ## Sample test
 
 ```
-docker run --rm -v $(pwd):/src docksal/backstopjs genConfig
+docker run --rm -v $(pwd):/src docksal/backstopjs init
 docker run --rm -v $(pwd):/src docksal/backstopjs reference
 docker run --rm -v $(pwd):/src docksal/backstopjs test
 ```
 
 
-## PhantomJS/SlimerJS
+## Browser engines
 
-By default BackstopJS is using PhantomJS to take screenshots.  
-You can also use SlimerJS/Firefox by setting `"engine": "slimerjs"` 
-in the [configuration file](tests/backstop/backstop-example.json).
+By default BackstopJS is using Headless Chrome to take screenshots.
 
-Both SlimerJS and Firefox ESR (extended support release) are installed in the container.
+You can also use PhantomJS or SlimerJS/Firefox by setting `"engine": "phantomjs"` or `"engine": "slimerjs"` respectively 
+in `backstop.json`.
+
+Chrome, PhantomJS, SlimerJS and Firefox ESR (extended support release) are pre-installed in the container.
 
 
 ## Limitations
 
 `backstop openReport` is not (yet) supported.  
 You will need a running webserver to view HTML reports generated by BackstopJS.
 
-When running SlimerJS, the user you are running the container as must have a home directory in order for Slimer to start properly.  You can work around this by setting the HOME variable.  Ex:
+When running SlimerJS, the user you are running the container as must have a home directory in order for Slimer 
+to start properly. You can work around this by setting the `HOME` variable:
+
 ```
 docker run --rm --user 1000 -e HOME=/tmp/home docksal/backstopjs test
 ```
 
+
 ## Debugging
 
 The following command will start a bash session in the container.

tests/test.bats

@@ -0,0 +1,79 @@
+#!/usr/bin/env bats
+
+PHANTOMJS_VERSION=2.1.1
+CASPERJS_VERSION=1.1.4
+SLIMERJS_VERSION=0.10.3
+BACKSTOPJS_VERSION=3.0.25
+CHROMIUM_VERSION=61.0
+FIREFOX_VERSION=52.3
+
+# Debugging
+teardown() {
+	echo
+	# TODO: figure out how to deal with this (output from previous run commands showing up along with the error message)
+	echo "Note: ignore the lines between \"...failed\" above and here"
+	echo
+	echo "Status: $status"
+	echo "Output:"
+	echo "================================================================"
+	echo "$output"
+	echo "================================================================"
+}
+
+# Global skip
+# Uncomment below, then comment skip in the test you want to debug. When done, reverse.
+#SKIP=1
+
+@test "Check PhantomJS" {
+	[[ $SKIP == 1 ]] && skip
+
+	### Tests ###
+
+	run fin docker run --name ${NAME} --rm --entrypoint="" ${IMAGE} phantomjs --version
+	echo "$output" | grep -F ${PHANTOMJS_VERSION}
+}
+
+@test "Check SlimerJS" {
+	[[ $SKIP == 1 ]] && skip
+
+	### Tests ###
+
+	run fin docker run --name ${NAME} --rm --entrypoint="" ${IMAGE} slimerjs --version
+	echo "$output" | grep -F ${SLIMERJS_VERSION}
+}
+
+@test "Check CasperJS" {
+	[[ $SKIP == 1 ]] && skip
+
+	### Tests ###
+
+	run fin docker run --name ${NAME} --rm --entrypoint="" ${IMAGE} casperjs --version
+	echo "$output" | grep -F ${CASPERJS_VERSION}
+}
+
+@test "Check BackstopJS" {
+	[[ $SKIP == 1 ]] && skip
+
+	### Tests ###
+
+	run fin docker run --name ${NAME} --rm --entrypoint="" ${IMAGE} backstop --version
+	echo "$output" | grep -F ${BACKSTOPJS_VERSION}
+}
+
+@test "Check Chrome" {
+	[[ $SKIP == 1 ]] && skip
+
+	### Tests ###
+
+	run fin docker run --name ${NAME} --rm --entrypoint="" ${IMAGE} chromium-browser --version
+	echo "$output" | grep -F ${CHROMIUM_VERSION}
+}
+
+@test "Check Firefox" {
+	[[ $SKIP == 1 ]] && skip
+
+	### Tests ###
+
+	run fin docker run --name ${NAME} --rm --entrypoint="" ${IMAGE} firefox --version
+	echo "$output" | grep ${FIREFOX_VERSION}
+}