Add a lib to extract update metadata from commit messages

src/dependabot/update_metadata.test.ts

@@ -0,0 +1,101 @@
+import * as updateMetadata from './update_metadata'
+
+test('it returns an empty array for a blank string', async () => {
+  expect(updateMetadata.parse('')).toEqual([])
+})
+
+test('it returns an empty array for commit message with no dependabot yaml fragment', async () => {
+  const commitMessage = `Bumps [coffee-rails](https://github.com/rails/coffee-rails) from 4.0.1 to 4.2.2.
+  - [Release notes](https://github.com/rails/coffee-rails/releases)
+  - [Changelog](https://github.com/rails/coffee-rails/blob/master/CHANGELOG.md)
+  - [Commits](rails/coffee-rails@v4.0.1...v4.2.2)
+
+  Signed-off-by: dependabot[bot] <support@github.com>`
+
+  expect(updateMetadata.parse(commitMessage)).toEqual([])
+})
+
+test('it returns the updated dependency information when there is a yaml fragment', async () => {
+  const commitMessage = `Bumps [coffee-rails](https://github.com/rails/coffee-rails) from 4.0.1 to 4.2.2.
+  - [Release notes](https://github.com/rails/coffee-rails/releases)
+  - [Changelog](https://github.com/rails/coffee-rails/blob/master/CHANGELOG.md)
+  - [Commits](rails/coffee-rails@v4.0.1...v4.2.2)
+
+  ---
+  updated-dependencies:
+  - dependency-name: coffee-rails
+    dependency-type: direct:production
+    update-type: version-update:semver-minor
+  ...
+
+  Signed-off-by: dependabot[bot] <support@github.com>`
+
+  const updatedDependencies = updateMetadata.parse(commitMessage)
+
+  expect(updatedDependencies).toHaveLength(1)
+
+  expect(updatedDependencies[0].name).toEqual('coffee-rails')
+  expect(updatedDependencies[0].type).toEqual('direct:production')
+  expect(updatedDependencies[0].updateType).toEqual('version-update:semver-minor')
+})
+
+test('it supports multiple dependencies within a single fragment', async () => {
+  const commitMessage = `Bumps [coffee-rails](https://github.com/rails/coffee-rails) from 4.0.1 to 4.2.2.
+  - [Release notes](https://github.com/rails/coffee-rails/releases)
+  - [Changelog](https://github.com/rails/coffee-rails/blob/master/CHANGELOG.md)
+  - [Commits](rails/coffee-rails@v4.0.1...v4.2.2)
+
+  ---
+  updated-dependencies:
+  - dependency-name: coffee-rails
+    dependency-type: direct:production
+    update-type: version-update:semver-minor
+  - dependency-name: coffeescript
+    dependency-type: indirect:production
+    update-type: version-update:semver-patch
+  ...
+
+  Signed-off-by: dependabot[bot] <support@github.com>`
+
+  const updatedDependencies = updateMetadata.parse(commitMessage)
+
+  expect(updatedDependencies).toHaveLength(2)
+
+  expect(updatedDependencies[0].name).toEqual('coffee-rails')
+  expect(updatedDependencies[0].type).toEqual('direct:production')
+  expect(updatedDependencies[0].updateType).toEqual('version-update:semver-minor')
+
+  expect(updatedDependencies[1].name).toEqual('coffeescript')
+  expect(updatedDependencies[1].type).toEqual('indirect:production')
+  expect(updatedDependencies[1].updateType).toEqual('version-update:semver-patch')
+})
+
+test('it only returns information within the first fragment if there are multiple yaml documents', async () => {
+  const commitMessage = `Bumps [coffee-rails](https://github.com/rails/coffee-rails) from 4.0.1 to 4.2.2.
+  - [Release notes](https://github.com/rails/coffee-rails/releases)
+  - [Changelog](https://github.com/rails/coffee-rails/blob/master/CHANGELOG.md)
+  - [Commits](rails/coffee-rails@v4.0.1...v4.2.2)
+
+  ---
+  updated-dependencies:
+  - dependency-name: coffee-rails
+    dependency-type: direct:production
+    update-type: version-update:semver-minor
+  ...
+  ---
+  updated-dependencies:
+  - dependency-name: coffeescript
+    dependency-type: indirect:production
+    update-type: version-update:semver-patch
+  ...
+
+  Signed-off-by: dependabot[bot] <support@github.com>`
+
+  const updatedDependencies = updateMetadata.parse(commitMessage)
+
+  expect(updatedDependencies).toHaveLength(1)
+
+  expect(updatedDependencies[0].name).toEqual('coffee-rails')
+  expect(updatedDependencies[0].type).toEqual('direct:production')
+  expect(updatedDependencies[0].updateType).toEqual('version-update:semver-minor')
+})

src/dependabot/update_metadata.ts

@@ -0,0 +1,27 @@
+import * as YAML from 'yaml'
+
+interface updatedDependency {
+  name: string,
+  type: string,
+  updateType: string,
+}
+
+export function parse (commitMessage: string): Array<updatedDependency> {
+  const yamlFragment = commitMessage.match(/-{3}\n(?<dependencies>[\S|\s]*?)(?=\s*\.{3}\n)/m)
+
+  if (yamlFragment?.groups) {
+    const data = YAML.parse(yamlFragment.groups.dependencies)
+
+    if (data['updated-dependencies']) {
+      return data['updated-dependencies'].map(dependency => {
+        return {
+          name: dependency['dependency-name'],
+          type: dependency['dependency-type'],
+          updateType: dependency['update-type']
+        }
+      })
+    }
+  }
+
+  return []
+}