feat: Add regex validation for subject (#71)

* feat: Add regex validation for subject

* Update yml

* Remove config

* Reenable

* Add logging

* Fix assignment

* Remove config

README.md

@@ -32,7 +32,7 @@ jobs:
   main:
     runs-on: ubuntu-latest
     steps:
-      - uses: amannn/action-semantic-pull-request@v2.1.0
+      - uses: amannn/action-semantic-pull-request@v3.1.0
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         # Optionally, you can provide options for further constraints.
@@ -48,6 +48,9 @@ jobs:
             ui
           # Configure that a scope must always be provided.
           requireScope: true
+          # Configure additional validation for the subject based on a regex.
+          # This example ensures the subject doesn't start with an uppercase character.
+          subjectPattern: ^(?![A-Z]).+$
           # For work-in-progress PRs you can typically use draft pull requests 
           # from Github. However, private repositories on the free plan don't have 
           # this option and therefore this action allows you to opt-in to using the 

action.yml

@@ -17,6 +17,9 @@ inputs:
   requireScope:
     description: "Configure that a scope must always be provided."
     required: false
+  subjectPattern:
+    description: "Configure additional validation for the subject based on a regex. E.g. '^(?![A-Z]).+$' ensures the subject doesn't start with an uppercase character."
+    required: false
   wip:
     description: "For work-in-progress PRs you can typically use draft pull requests from Github. However, private repositories on the free plan don't have this option and therefore this action allows you to opt-in to using the special '[WIP]' prefix to indicate this state. This will avoid the validation of the PR title and the pull request checks remain pending. Note that a second check will be reported if this is enabled."
     required: false

src/ConfigParser.js

@@ -10,5 +10,9 @@ module.exports = {
 
   parseBoolean(input) {
     return JSON.parse(input.trim());
+  },
+
+  parseString(input) {
+    return input;
   }
 };

src/index.js

@@ -6,7 +6,7 @@ const validatePrTitle = require('./validatePrTitle');
 module.exports = async function run() {
   try {
     const client = github.getOctokit(process.env.GITHUB_TOKEN);
-    const {types, scopes, requireScope, wip} = parseConfig();
+    const {types, scopes, requireScope, wip, subjectPattern} = parseConfig();
 
     const contextPullRequest = github.context.payload.pull_request;
     if (!contextPullRequest) {
@@ -34,7 +34,12 @@ module.exports = async function run() {
     let validationError;
     if (!isWip) {
       try {
-        await validatePrTitle(pullRequest.title, {types, scopes, requireScope});
+        await validatePrTitle(pullRequest.title, {
+          types,
+          scopes,
+          requireScope,
+          subjectPattern
+        });
       } catch (error) {
         validationError = error;
       }

src/parseConfig.js

@@ -16,10 +16,15 @@ module.exports = function parseConfig() {
     requireScope = ConfigParser.parseBoolean(process.env.INPUT_REQUIRESCOPE);
   }
 
+  let subjectPattern;
+  if (process.env.INPUT_SUBJECTPATTERN) {
+    subjectPattern = ConfigParser.parseString(process.env.INPUT_SUBJECTPATTERN);
+  }
+
   let wip;
   if (process.env.INPUT_WIP) {
     wip = ConfigParser.parseBoolean(process.env.INPUT_WIP);
   }
 
-  return {types, scopes, requireScope, wip};
+  return {types, scopes, requireScope, wip, subjectPattern};
 };

src/validatePrTitle.js

@@ -6,7 +6,7 @@ const defaultTypes = Object.keys(conventionalCommitTypes.types);
 
 module.exports = async function validatePrTitle(
   prTitle,
-  {types, scopes, requireScope} = {}
+  {types, scopes, requireScope, subjectPattern} = {}
 ) {
   if (!types) types = defaultTypes;
 
@@ -33,6 +33,10 @@ module.exports = async function validatePrTitle(
     );
   }
 
+  if (!result.subject) {
+    throw new Error(`No subject found in pull request title "${prTitle}".`);
+  }
+
   if (!types.includes(result.type)) {
     throw new Error(
       `Unknown release type "${
@@ -58,4 +62,21 @@ module.exports = async function validatePrTitle(
       )}.`
     );
   }
+
+  if (subjectPattern) {
+    const match = result.subject.match(new RegExp(subjectPattern));
+
+    if (!match) {
+      throw new Error(
+        `The subject "${result.subject}" found in pull request title "${prTitle}" doesn't match the configured pattern "${subjectPattern}".`
+      );
+    }
+
+    const matchedPart = match[0];
+    if (matchedPart.length !== result.subject.length) {
+      throw new Error(
+        `The subject "${result.subject}" found in pull request title "${prTitle}" isn't an exact match for the configured pattern "${subjectPattern}". Please provide a subject that matches the whole pattern exactly.`
+      );
+    }
+  }
 };

src/validatePrTitle.test.js

@@ -20,6 +20,18 @@ it('throws for PR titles without a type', async () => {
   );
 });
 
+it('throws for PR titles with only a type', async () => {
+  await expect(validatePrTitle('fix:')).rejects.toThrow(
+    'No release type found in pull request title "fix:".'
+  );
+});
+
+it('throws for PR titles without a subject', async () => {
+  await expect(validatePrTitle('fix: ')).rejects.toThrow(
+    'No subject found in pull request title "fix: ".'
+  );
+});
+
 it('throws for PR titles with an unknown type', async () => {
   await expect(validatePrTitle('foo: Bar')).rejects.toThrow(
     'Unknown release type "foo" found in pull request title "foo: Bar".'
@@ -90,3 +102,35 @@ describe('custom types', () => {
     );
   });
 });
+
+describe('description validation', () => {
+  it('does not validate the description by default', async () => {
+    await validatePrTitle('fix: sK!"§4123');
+  });
+
+  it('throws for invalid subjects', async () => {
+    await expect(
+      validatePrTitle('fix: Foobar', {
+        subjectPattern: '^(?![A-Z]).+$'
+      })
+    ).rejects.toThrow(
+      'The subject "Foobar" found in pull request title "fix: Foobar" doesn\'t match the configured pattern "^(?![A-Z]).+$".'
+    );
+  });
+
+  it('throws for only partial matches', async () => {
+    await expect(
+      validatePrTitle('fix: Foobar', {
+        subjectPattern: 'Foo'
+      })
+    ).rejects.toThrow(
+      'The subject "Foobar" found in pull request title "fix: Foobar" isn\'t an exact match for the configured pattern "Foo". Please provide a subject that matches the whole pattern exactly.'
+    );
+  });
+
+  it('accepts valid subjects', async () => {
+    await validatePrTitle('fix: foobar', {
+      subjectPattern: '^(?![A-Z]).+$'
+    });
+  });
+});