Allow negative patterns to be used in an array

README.md

@@ -45,6 +45,21 @@ Then if a pull request is opened with the branch name `feature/218-add-emoji-sup
 
 You can use `*` as a wildcard for matching multiple branch names. See https://www.npmjs.com/package/matcher for more information about wildcard options.
 
+### Negative matcher
+
+You can also use `!` to add a label on all branches that does NOT match the pattern.
+
+Used in a list of patterns, then, the branch name will have to match all patterns.
+
+For example:
+
+```yml
+patch: ['update/*', '!update/sbt-*']
+no-release: update/sbt-*
+```
+
+In this scenario, a branch named `update/sbt-native-package` will only have the `no-release` label
+
 ### Default configuration
 
 When no configuration is provided, the following defaults will be used:

__tests__/action.test.ts

@@ -76,6 +76,22 @@ describe('pr-labeler-action', () => {
     expect.assertions(1)
   })
 
+  it("adds only one label if the branch matches a negative pattern", async () => {
+    nock('https://api.github.com')
+        .get('/repos/Codertocat/Hello-World/contents/.github/pr-labeler.yml?ref=release%2Fskip-this-one')
+        .reply(200, configFixture())
+        .post('/repos/Codertocat/Hello-World/issues/1/labels', body => {
+          expect(body).toMatchObject({
+            labels: ['skip-release']
+          })
+          return true
+        })
+        .reply(200)
+
+    await action(new MockContext(pullRequestOpenedFixture({ ref: 'release/skip-this-one' })))
+    expect.assertions(1)
+  })
+
   it("adds no labels if the branch doesn't match any patterns", async () => {
     nock('https://api.github.com')
       .get('/repos/Codertocat/Hello-World/contents/.github/pr-labeler.yml?ref=hello_world')

__tests__/fixtures/config.yml

@@ -1,4 +1,5 @@
 '🎉 feature': ['feature/*', 'feat/*']
 fix: fix/*
 chore: chore/*
-release: release/*
+release: ['release/*', '!release/skip-*']
+skip-release: release/skip-*

src/action.ts

@@ -45,11 +45,14 @@ async function action(context: Context = github.context) {
 
 function getLabelsToAdd(config: Config, branchName: string): string[] {
   return Object.entries(config).reduce(
-    (labels, [label, patterns]) => {
+
+    (labels, [label, pattern]) => {
+      const patterns = Array.isArray(pattern) ? pattern : [pattern]
+
       if (
-        Array.isArray(patterns)
-          ? patterns.some(pattern => matcher.isMatch(branchName, pattern))
-          : matcher.isMatch(branchName, patterns)
+        patterns.some(pattern => pattern.startsWith("!"))
+            ? patterns.every(pattern => matcher.isMatch(branchName, pattern))
+            : patterns.some(pattern => matcher.isMatch(branchName, pattern))
       ) {
         labels.push(label)
       }