feat(presets): add merge confidence preset (#23215)

Co-authored-by: Rhys Arkins <rhys@arkins.net>
Co-authored-by: HonkingGoose <34918129+HonkingGoose@users.noreply.github.com>

docs/usage/merge-confidence.md

@@ -0,0 +1,98 @@
+# Merge Confidence
+
+Look at the Merge Confidence badges before merging to:
+
+- Prevent updates which break in production
+- See at a glance if you should update
+
+Merge Confidence finds and flags undeclared breaking releases.
+It analyzes test and release adoption data across Mend Renovate’s early-adopting user base.
+
+![Renovate PR with Merge Confidence badges](assets/images/merge-confidence.png)
+
+## Pull request badges
+
+Merge Confidence adds the following badges to your pull requests:
+
+- **Age**: The age of the package
+- **Adoption**: The percentage of this package's users (within Renovate) which are using this release
+- **Passing**: The percentage of updates which have passing tests for this package
+- **Confidence**: The confidence level for this update
+
+## Supported platforms
+
+Merge Confidence badges for pull requests are available on any supported platform or Renovate distribution, including Mend Remediate.
+
+## Supported languages
+
+Data is available for packages from:
+
+- npm
+- Maven
+- PyPI
+
+We plan to support more languages soon.
+
+## Enabling and disabling
+
+If you use the Mend Renovate App then the badges are enabled automatically.
+
+If you're self-hosting Renovate, you can enable the badges by adding the `mergeConfidence:all-badges` preset to the `extends` array in your Renovate config:
+
+```json
+{
+  "extends": ["mergeConfidence:all-badges"]
+}
+```
+
+<!-- prettier-ignore -->
+!!! note
+    The `mergeConfidence:age-confidence-badges` preset can be used to only show the Age and Confidence badges.
+
+If you want to disable the badges in the app, add the `mergeConfidence:all-badges` preset to the `ignorePresets` array in your config:
+
+```json
+{
+  "ignorePresets": ["mergeConfidence:all-badges"]
+}
+```
+
+## Confidence levels and their meaning
+
+Merge Confidence uses the following confidence levels:
+
+- **Low**: We think the update contains breaking changes. Often this is expected because it's a `major` version update, but updates can have unknown breaking changes
+- **Neutral**: We don't have enough data about the update, or we can't decide if the update should be Low or High confidence
+- **High**: We rank updates as High confidence when the combination of `Age`, `Adoption` and `Passing` tests means there's a very low chance of breaking changes
+- **Very High**: We only use this for updates which are months old and have either high `Adoption` or have very high test `Passing` scores
+
+## How it works
+
+Mend's hosted Renovate App has created millions of pull requests on `github.com` to help developers update their dependencies since 2017.
+We bundle and analyze metrics such as package `Age`, package `Adoption`, and `Passing` tests.
+This way we can find packages that have undeclared breaking changes.
+
+### Algorithm
+
+The algorithm that decides on the values is private and is not something we plan to share.
+Similar to a search engine's algorithm, we plan to adjust and improve it over time, for example by using historical data to set a baseline confidence level for packages.
+
+### Data
+
+We plan to expose much more of the data via a companion website, such as number of users of a package and popular repositories which already updated to the version in question.
+
+## Explanations
+
+### Package ranking
+
+npm packages less than three days old can be [unpublished](https://docs.npmjs.com/policies/unpublish), which can result in a service impact if you have updated to a package that gets unpublished.
+This is why npm packages can only get the **High** Confidence badge when they are at least three days old.
+
+### Percentage values weighting
+
+The percentages for `Adoption` and `Passing` are weighted towards Organizations, private repositories, and projects with high test reliability.
+This means those values aren't _raw_ percentages.
+
+## Questions and feedback
+
+You are invited to [start a discussion](https://github.com/renovatebot/renovate/discussions/new/choose) if you have anything you'd like to discuss.

lib/config/migrations/custom/extends-migration.spec.ts

@@ -72,4 +72,15 @@ describe('config/migrations/custom/extends-migration', () => {
     );
     GlobalConfig.reset();
   });
+
+  it('migrate merge confidence config preset to internal preset', () => {
+    expect(ExtendsMigration).toMigrate(
+      {
+        extends: ['github>whitesource/merge-confidence:beta'],
+      },
+      {
+        extends: ['mergeConfidence:all-badges'],
+      }
+    );
+  });
 });

lib/config/options/index.ts

@@ -2341,6 +2341,13 @@ const options: RenovateOptions[] = [
       Pending: '{{{displayPending}}}',
       References: '{{{references}}}',
       'Package file': '{{{packageFile}}}',
+      Age: "[![age](https://developer.mend.io/api/mc/badges/age/{{datasource}}/{{replace '/' '%2f' depName}}/{{{newVersion}}}?slim=true)](https://docs.renovatebot.com/merge-confidence/)",
+      Adoption:
+        "[![adoption](https://developer.mend.io/api/mc/badges/adoption/{{datasource}}/{{replace '/' '%2f' depName}}/{{{newVersion}}}?slim=true)](https://docs.renovatebot.com/merge-confidence/)",
+      Passing:
+        "[![passing](https://developer.mend.io/api/mc/badges/compatibility/{{datasource}}/{{replace '/' '%2f' depName}}/{{{currentVersion}}}/{{{newVersion}}}?slim=true)](https://docs.renovatebot.com/merge-confidence/)",
+      Confidence:
+        "[![confidence](https://developer.mend.io/api/mc/badges/confidence/{{datasource}}/{{replace '/' '%2f' depName}}/{{{currentVersion}}}/{{{newVersion}}}?slim=true)](https://docs.renovatebot.com/merge-confidence/)",
     },
   },
   {

lib/config/presets/common.ts

@@ -27,6 +27,7 @@ export const removedPresets: Record<string, string | null> = {
   'helpers:oddIsUnstable': null,
   'helpers:oddIsUnstablePackages': null,
   'group:jsTestMonMajor': 'group:jsTestNonMajor',
+  'github>whitesource/merge-confidence:beta': 'mergeConfidence:all-badges',
 };
 
 const renamedMonorepos: Record<string, string> = {

lib/config/presets/index.ts

@@ -140,6 +140,7 @@ export function parsePreset(input: string): ParsedPreset {
     'docker',
     'group',
     'helpers',
+    'mergeConfidence',
     'monorepo',
     'npm',
     'packages',

lib/config/presets/internal/index.ts

@@ -4,6 +4,7 @@ import * as defaultPreset from './default';
 import * as dockerPreset from './docker';
 import * as groupPreset from './group';
 import * as helpersPreset from './helpers';
+import * as mergeConfidence from './merge-confidence';
 import * as monorepoPreset from './monorepo';
 import * as npm from './npm';
 import * as packagesPreset from './packages';
@@ -21,6 +22,7 @@ export const groups: Record<string, Record<string, Preset>> = {
   docker: dockerPreset.presets,
   group: groupPreset.presets,
   helpers: helpersPreset.presets,
+  mergeConfidence: mergeConfidence.presets,
   monorepo: monorepoPreset.presets,
   npm: npm.presets,
   packages: packagesPreset.presets,

lib/config/presets/internal/merge-confidence.ts

@@ -0,0 +1,32 @@
+import type { Preset } from '../types';
+
+export const presets: Record<string, Preset> = {
+  'all-badges': {
+    description: 'Show all Merge Confidence badges for pull requests.',
+    packageRules: [
+      {
+        matchDatasources: ['maven', 'npm', 'pypi'],
+        matchUpdateTypes: ['patch', 'minor', 'major'],
+        prBodyColumns: [
+          'Package',
+          'Change',
+          'Age',
+          'Adoption',
+          'Passing',
+          'Confidence',
+        ],
+      },
+    ],
+  },
+  'age-confidence-badges': {
+    description:
+      'Show only the Age and Confidence Merge Confidence badges for pull requests.',
+    packageRules: [
+      {
+        matchDatasources: ['maven', 'npm', 'pypi'],
+        matchUpdateTypes: ['patch', 'minor', 'major'],
+        prBodyColumns: ['Package', 'Change', 'Age', 'Confidence'],
+      },
+    ],
+  },
+};