Merge branch 'alberts-jest-related-tests' into 'master'

Run jest related tests on CI on frontend changes

See merge request gitlab-org/gitlab!68251

.gitlab/ci/frontend.gitlab-ci.yml

@@ -172,6 +172,8 @@ graphql-schema-dump:
     # Disable warnings in browserslist which can break on backports
     # https://github.com/browserslist/browserslist/blob/a287ec6/node.js#L367-L384
     BROWSERSLIST_IGNORE_OLD_DATA: "true"
+  before_script:
+    - *yarn-install
   stage: test
 
 eslint-as-if-foss:
@@ -181,20 +183,19 @@ eslint-as-if-foss:
     - .as-if-foss
   needs: []
   script:
-    - *yarn-install
     - run_timed_command "yarn run lint:eslint:all"
 
 .jest-base:
   extends: .frontend-test-base
   script:
-    - *yarn-install
-    - run_timed_command "yarn jest --ci --coverage --testSequencer ./scripts/frontend/parallel_ci_sequencer.js"
+    - run_timed_command "yarn jest:ci"
 
 jest:
   extends:
     - .jest-base
-    - .frontend:rules:default-frontend-jobs
+    - .frontend:rules:jest
   needs:
+    - job: "detect-tests"
     - job: "rspec frontend_fixture"
     - job: "rspec-ee frontend_fixture"
       optional: true
@@ -210,12 +211,18 @@ jest:
       junit: junit_jest.xml
   parallel: 5
 
+jest minimal:
+  extends:
+    - jest
+    - .frontend:rules:jest:minimal
+  script:
+    - run_timed_command "yarn jest:ci:minimal"
+
 jest-integration:
   extends:
     - .frontend-test-base
     - .frontend:rules:default-frontend-jobs
   script:
-    - *yarn-install
     - run_timed_command "yarn jest:integration --ci"
   needs:
     - job: "rspec frontend_fixture"
@@ -236,7 +243,11 @@ coverage-frontend:
     - .default-retry
     - .yarn-cache
     - .frontend:rules:ee-mr-and-default-branch-only
-  needs: ["jest"]
+  needs:
+    - job: "jest"
+      optional: true
+    - job: "jest minimal"
+      optional: true
   stage: post-test
   before_script:
     - *yarn-install
@@ -321,7 +332,6 @@ bundle-size-review:
   extends:
     - .frontend-test-base
   script:
-    - *yarn-install
     - run_timed_command "yarn generate:startup_css"
     - yarn check:startup_css
 
@@ -349,7 +359,6 @@ startup-css-check as-if-foss:
     - .frontend-test-base
     - .storybook-yarn-cache
   script:
-    - *yarn-install  # storybook depends on the global webpack config, so we must install global deps.
     - *storybook-yarn-install
     - yarn run storybook:build
 

.gitlab/ci/rules.gitlab-ci.yml

@@ -46,6 +46,9 @@
 .if-merge-request-title-run-all-rspec: &if-merge-request-title-run-all-rspec
   if: '$CI_MERGE_REQUEST_LABELS =~ /pipeline:run-all-rspec/'
 
+.if-merge-request-title-run-all-jest: &if-merge-request-title-run-all-jest
+  if: '$CI_MERGE_REQUEST_LABELS =~ /pipeline:run-all-jest/'
+
 .if-merge-request-run-decomposed: &if-merge-request-run-decomposed
   if: '$CI_MERGE_REQUEST_LABELS =~ /pipeline:run-decomposed/'
 
@@ -365,6 +368,14 @@
   - "danger/**/*"
   - "tooling/danger/**/*"
 
+.core-frontend-patterns: &core-frontend-patterns
+  - "{package.json,yarn.lock}"
+  - "babel.config.js"
+  - "jest.config.{base,integration,unit}.js"
+  - "config/helpers/**/*.js"
+  - "vendor/assets/javascripts/**/*"
+  - "{,ee}/app/assets/**/*.graphql"
+
 ################
 # Shared rules #
 ################
@@ -525,6 +536,37 @@
     - <<: *if-merge-request
       changes: *ci-patterns
 
+.frontend:rules:jest:
+  rules:
+    - <<: *if-merge-request-title-run-all-jest
+    - <<: *if-default-refs
+      changes: *core-frontend-patterns
+    - <<: *if-merge-request
+      changes: *ci-patterns
+    - <<: *if-automated-merge-request
+      changes: *code-backstage-patterns
+    - <<: *if-merge-request-not-approved
+      when: never
+    - <<: *if-default-refs
+      changes: *code-backstage-patterns
+
+.frontend:rules:jest:minimal:
+  rules:
+    - <<: *if-merge-request-approved
+      when: never
+    - <<: *if-automated-merge-request
+      when: never
+    - <<: *if-merge-request-title-run-all-jest
+      when: never
+    - <<: *if-default-refs
+      changes: *core-frontend-patterns
+      when: never
+    - <<: *if-merge-request
+      changes: *ci-patterns
+      when: never
+    - <<: *if-merge-request
+      changes: *code-backstage-patterns
+
 .frontend:rules:eslint-as-if-foss:
   rules:
     - <<: *if-not-ee

.gitlab/ci/setup.gitlab-ci.yml

@@ -70,11 +70,16 @@ verify-tests-yml:
     - install_gitlab_gem
     - install_tff_gem
     - retrieve_tests_mapping
-    - 'if [ -n "$CI_MERGE_REQUEST_IID" ]; then tooling/bin/find_tests ${MATCHED_TESTS_FILE}; fi'
-    - 'if [ -n "$CI_MERGE_REQUEST_IID" ]; then echo "test files affected: $(cat $MATCHED_TESTS_FILE)"; fi'
+    - |
+      if [ -n "$CI_MERGE_REQUEST_IID" ]; then
+        tooling/bin/find_changes ${CHANGES_FILE};
+        tooling/bin/find_tests ${CHANGES_FILE} ${MATCHED_TESTS_FILE};
+        echo "related rspec tests: $(cat $MATCHED_TESTS_FILE)";
+      fi
   artifacts:
     expire_in: 7d
     paths:
+      - ${CHANGES_FILE}
       - ${MATCHED_TESTS_FILE}
 
 detect-tests:
@@ -83,6 +88,7 @@ detect-tests:
     - .rails:rules:detect-tests
   variables:
     RSPEC_TESTS_MAPPING_ENABLED: "true"
+    CHANGES_FILE: tmp/changed_files.txt
     MATCHED_TESTS_FILE: tmp/matching_tests.txt
 
 detect-tests as-if-foss:
@@ -91,6 +97,7 @@ detect-tests as-if-foss:
     - .rails:rules:detect-tests
     - .as-if-foss
   variables:
+    CHANGES_FILE: tmp/changed_foss_files.txt
     MATCHED_TESTS_FILE: tmp/matching_foss_tests.txt
   before_script:
     - '[ "$FOSS_ONLY" = "1" ] && rm -rf ee/ qa/spec/ee/ qa/qa/specs/features/ee/ qa/qa/ee/ qa/qa/ee.rb'

doc/development/pipelines.md

@@ -430,6 +430,23 @@ In the `detect-tests` job, we use this mapping to identify the minimal tests nee
 After a merge request has been approved, the pipeline would contain the full RSpec tests. This will ensure that all tests
 have been run before a merge request is merged.
 
+### Jest minimal jobs
+
+Before a merge request is approved, the pipeline will run a minimal set of Jest tests that are related to the merge request changes.
+This is to reduce the pipeline cost and shorten the job duration.
+
+To identify the minimal set of tests needed, we pass a list of all the changed files into `jest` using the [`--findRelatedTests`](https://jestjs.io/docs/cli#--findrelatedtests-spaceseparatedlistofsourcefiles) option.
+In this mode, `jest` would resolve all the dependencies of related to the changed files, which include test files that have these files in the dependency chain.
+
+After a merge request has been approved, the pipeline would contain the full Jest tests. This will ensure that all tests
+have been run before a merge request is merged.
+
+In addition, there are a few circumstances where we would always run the full Jest tests:
+
+- when `package.json`, `yarn.lock`, `jest` config changes
+- when vendored JavaScript is changed
+- when `.graphql` files are changed
+
 ### PostgreSQL versions testing
 
 Our test suite runs against PG12 as GitLab.com runs on PG12 and

package.json

@@ -13,6 +13,8 @@
     "prejest": "yarn check-dependencies",
     "jest": "jest --config jest.config.js",
     "jest-debug": "node --inspect-brk node_modules/.bin/jest --runInBand",
+    "jest:ci": "jest --config jest.config.js --ci --coverage --testSequencer ./scripts/frontend/parallel_ci_sequencer.js",
+    "jest:ci:minimal": "jest --config jest.config.js --ci --coverage --findRelatedTests $(cat tmp/changed_files.txt) --passWithNoTests --testSequencer ./scripts/frontend/parallel_ci_sequencer.js",
     "jest:integration": "jest --config jest.config.integration.js",
     "jsdoc": "jsdoc -c config/jsdocs.config.js",
     "lint:eslint": "yarn run internal:eslint",

tooling/bin/find_changes

+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require 'gitlab'
+
+gitlab_token = ENV.fetch('DANGER_GITLAB_API_TOKEN', '')
+gitlab_endpoint = ENV.fetch('CI_API_V4_URL')
+mr_project_path = ENV.fetch('CI_MERGE_REQUEST_PROJECT_PATH')
+mr_iid = ENV.fetch('CI_MERGE_REQUEST_IID')
+
+output_file = ARGV.shift
+
+Gitlab.configure do |config|
+  config.endpoint       = gitlab_endpoint
+  config.private_token  = gitlab_token
+end
+
+mr_changes = Gitlab.merge_request_changes(mr_project_path, mr_iid)
+file_changes = mr_changes.changes.map { |change| change['new_path'] }
+
+File.write(output_file, file_changes.join(' '))

tooling/bin/find_tests

 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
-require 'gitlab'
 require 'test_file_finder'
 
-gitlab_token = ENV.fetch('DANGER_GITLAB_API_TOKEN', '')
-gitlab_endpoint = ENV.fetch('CI_API_V4_URL')
-
-Gitlab.configure do |config|
-  config.endpoint       = gitlab_endpoint
-  config.private_token  = gitlab_token
-end
-
+changes = ARGV.shift
 output_file = ARGV.shift
 
-mr_project_path = ENV.fetch('CI_MERGE_REQUEST_PROJECT_PATH')
-mr_iid = ENV.fetch('CI_MERGE_REQUEST_IID')
-
-mr_changes = Gitlab.merge_request_changes(mr_project_path, mr_iid)
-changed_files = mr_changes.changes.map { |change| change['new_path'] }
+changed_files = File.read(changes).split(' ')
 
 tff = TestFileFinder::FileFinder.new(paths: changed_files).tap do |file_finder|
   file_finder.use TestFileFinder::MappingStrategies::PatternMatching.load('tests.yml')