Add unit and integration tests

.gitignore

@@ -22,3 +22,6 @@ ehthumbs_vista.db
 # IDE specific
 theme-sniffer.sublime-project
 theme-sniffer.sublime-workspace
+
+# Test coverage in HTML
+tests/_reports

.travis.yml

@@ -1,61 +1,69 @@
 dist: trusty
 
 cache:
-  apt: true
-  directories:
-    # Cache directory for older Composer versions.
-    - $HOME/.composer/cache/files
-    # Cache directory for more recent Composer versions.
-    - $HOME/.cache/composer/files
+	apt: true
+	directories:
+		# Cache directory for older Composer versions.
+		- $HOME/.composer/cache/files
+		# Cache directory for more recent Composer versions.
+		- $HOME/.cache/composer/files
 
 language: php
 
 php:
-  - 7.0
-  - 7.1
-  - 7.3
-  - nightly
+	- 7.0
+	- 7.1
+	- 7.3
+	- nightly
 
 env:
-  # Highest supported PHPCS version.
-  - PHPCS_BRANCH="dev-master" LINT=1
-  # Lowest supported PHPCS version.
-  - PHPCS_BRANCH="3.3.0"
+	# Highest supported PHPCS version.
+	- PHPCS_BRANCH="dev-master" LINT=1
+	# Lowest supported PHPCS version.
+	- PHPCS_BRANCH="3.3.0"
 
 notifications:
-  email:
-    on_success: never
-    on_failure: change
+	email:
+		on_success: never
+		on_failure: change
 
 branches:
-  only:
-    - master
-    - development
+	only:
+		- master
+		- development
 
 matrix:
-  fast_finish: true
-  include:
-    # Seperate builds for PHP 7.2 with additional checks.
-    - php: 7.2
-      env: PHPCS_BRANCH="dev-master"
-      addons:
-        apt:
-          packages:
-            - libxml2-utils
-    - php: 7.2
-      env: PHPCS_BRANCH="3.3.0"
-
-  allow_failures:
-    # Allow failures for unstable builds.
-    - php: nightly
-    - php: "7.4snapshot"
+	fast_finish: true
+	include:
+		# Seperate builds for PHP 7.2 with additional checks.
+		- php: 7.2
+			env: PHPCS_BRANCH="dev-master" LINT=1 SNIFF=1
+			addons:
+				apt:
+					packages:
+						- libxml2-utils
+		- php: 7.2
+			env: PHPCS_BRANCH="3.3.1"
+
+	allow_failures:
+		# Allow failures for unstable builds.
+		- php: nightly
+		- php: "7.4snapshot"
 
 before_install:
-  - phpenv config-rm xdebug.ini
-  - composer install
+	# Speed up build time by disabling Xdebug.
+	# https://johnblackbourn.com/reducing-travis-ci-build-times-for-wordpress-projects/
+	# https://twitter.com/kelunik/status/954242454676475904
+	- phpenv config-rm xdebug.ini || echo 'No xdebug config.'
+	- composer install
+	- bash bin/install-wp-tests.sh wordpress_test root '' localhost latest
 
 script:
-  # Lint the PHP files against parse errors.
-  - if find . -path ./vendor -prune -o -name "*.php" -exec php -l {} \; | grep "^[Parse error|Fatal error]"; then exit 1; fi;
-  # Check the codestyle of the WPThemeReview codebase.
-  - composer check-cs .
+	# Lint the PHP files against parse errors.
+	if find . -path ./vendor -prune -o -name "*.php" -exec php -l {} \; | grep "^[Parse error|Fatal error]"; then exit 1; fi
+	# Check the codestyle of the WPThemeReview codebase.
+	- composer check-cs .
+	# Run integration tests
+	- composer pint
+	# Run unit tests
+	- composer punit

Makefile

@@ -0,0 +1,59 @@
+#!make
+
+SETUP_TESTSUITE=bash bin/install-wp-tests.sh wordpress_test root '' localhost latest
+
+DEFAULT_GOAL := help
+help:
+	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m<target>\033[0m\n"} /^[a-zA-Z0-9_-]+:.*?##/ { printf "  \033[36m%-27s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)
+
+.PHONY: build-project
+build-project: ## Runs the npm and composer installations, and builds the zip file
+	composer install && npm install && npm run build
+
+.PHONY: build-dev
+build-dev: ## Runs the npm and composer installations without the zip file
+	composer install && npm install && npm run dev
+
+.PHONY: run-dev
+run-dev: ## Runs the dev npm script
+	npm run dev
+
+.PHONY: run-watch
+run-watch: ## Runs the watch npm script
+	npm run watch
+
+.PHONY: setup-testsuite
+setup-testsuite: ## Set up the default testsuite - install test WordPress and database
+	$(shell $(SETUP_TESTSUITE))
+
+.PHONY: clobber
+clobber: ## Run pcov clobber script - to use pcov instead of Xdebug
+	composer clobber
+
+.PHONY: unclobber
+unclobber: ## Run pcov unclobber script - to revert the usage of pcov instead of Xdebug
+	composer unclobber
+
+.PHONY: test-unit
+test-unit: ## Run unit tests
+	composer run-tests-unit
+
+.PHONY: test-unit-coverage
+test-unit-coverage: ## Run unit tests with code coverage
+	composer run-tests-unit-cov
+
+.PHONY: test-integration
+test-integration: ## Run integration tests
+	composer run-tests-integ
+
+.PHONY: test-integration-coverage
+test-integration-coverage: ## Run integration tests with code coverage
+	composer run-tests-integ-cov
+
+.PHONY: check-cs
+check-cs: ## Check the code with PHPCS against the coding standards
+	composer check-cs
+
+.PHONY: fix-cs
+fix-cs: ## Run the PHPCBF command for code beautification according to coding standards
+	composer fix-cs

README.md

@@ -106,4 +106,72 @@ When developing JavaScript code keep in mind the separation of concerns principl
 
 The same is valid for PHP code. The business logic is stored in the `src/` folder, the JS and CSS are located in `assets/` folder and the views are located in the `views/` folder.
 
+## Running unit or integration tests
 
+Before running unit tests, you'll need to install a local test environment. You can do this by running:
+
+```bash
+bash bin/install-wp-tests.sh wordpress_test root '' localhost latest
+```
+
+in your terminal.
+
+After this has been installed you can run
+
+```bash
+composer punit
+```
+
+to run unit tests (without coverage). To generate code coverage report you can run
+
+```bash
+composer punit-cov
+```
+
+In order for coverage to be generated, you'll need to have Xdebug installed.
+
+To run integration tests you can run
+
+```bash
+composer pint
+```
+
+To generate code coverage report you can run
+
+```bash
+composer pint-cov
+```
+
+The output should look like this:
+
+```bash
+> @php ./vendor/bin/phpunit -c phpunit.integration.xml.dist --no-coverage --colors=always
+Installing...
+Running as single site... To run multisite, use -c tests/phpunit/multisite.xml
+Not running ajax tests. To execute these, use --group ajax.
+Not running ms-files tests. To execute these, use --group ms-files.
+Not running external-http tests. To execute these, use --group external-http.
+
+PHPUnit Pretty Result Printer 0.20.3 by Codedungeon and contributors.
+==> Configuration: .../wp-content/plugins/theme-sniffer/vendor/codedungeon/phpunit-result-printer/phpunit-printer.yml
+
+PHPUnit 6.5.14 by Sebastian Bergmann and contributors.
+
+Runtime:       PHP 7.2.14 with Xdebug 2.6.1
+Configuration: .../wp-content/plugins/theme-sniffer/phpunit.integration.xml.dist
+
+
+ ==> Plugin_Integration_Test                    ✓  ✓  ✓  ✓  ✓  ✓
+
+Time: 4.43 seconds, Memory: 32.00MB
+```
+
+## Helpful Composer commands
+
+The plugin offers few additional helpful commands, but you'll mostly be interested in this one
+
+```bash
+composer check-cs .
+```
+
+It will run `phpcs` check on the entire code base.