Added output (#60)

* Added output

* removed formatting changes

* more formatting changes

* Fix merge conflicts

* Small test refactoring

* tests are passing

* Add a test

* Add a small jest mock for addLabels. Not used.

* Add tests for more cases

* get rid of an unused jest mock

* fix review points

* rebuild + minor README fix

* fix review points

* update tests

* fix formatting

* add tests, fix bug

* cleanup

---------

Co-authored-by: Daniel Shteremberg <[email protected]>
Co-authored-by: Daniel Shteremberg <[email protected]>
Co-authored-by: Patrick Ellis <[email protected]>
Co-authored-by: Andrey Lobanovich <[email protected]>

src/labeler.ts

@@ -43,8 +43,8 @@ export async function run() {
       configPath
     );
 
-    const prLabels: string[] = pullRequest.labels.map(label => label.name);
-    const allLabels: Set<string> = new Set(prLabels);
+    const preexistingLabels = pullRequest.labels.map(l => l.name);
+    const allLabels: Set<string> = new Set<string>(preexistingLabels);
 
     for (const [label, globs] of labelGlobs.entries()) {
       core.debug(`processing ${label}`);
@@ -55,14 +55,20 @@ export async function run() {
       }
     }
 
-    const labels = [...allLabels].slice(0, GITHUB_MAX_LABELS);
+    const labelsToAdd = [...allLabels].slice(0, GITHUB_MAX_LABELS);
     const excessLabels = [...allLabels].slice(GITHUB_MAX_LABELS);
 
     try {
-      if (!isListEqual(prLabels, labels)) {
-        await setLabels(client, prNumber, labels);
+      let newLabels: string[] = [];
+
+      if (!isListEqual(labelsToAdd, preexistingLabels)) {
+        await setLabels(client, prNumber, labelsToAdd);
+        newLabels = labelsToAdd.filter(l => !preexistingLabels.includes(l));
       }
 
+      core.setOutput('new-labels', newLabels.join(','));
+      core.setOutput('all-labels', labelsToAdd.join(','));
+
       if (excessLabels.length) {
         core.warning(
           `Maximum of ${GITHUB_MAX_LABELS} labels allowed. Excess labels: ${excessLabels.join(