feat(label): remove the stale label when labeled with an exempt one

closes actions#136

__tests__/main.test.ts

@@ -797,6 +797,7 @@ test('stale locked prs will not be closed', async () => {
 });
 
 test('exempt issue labels will not be marked stale', async () => {
+  expect.assertions(3);
   const TestIssueList: Issue[] = [
     generateIssue(1, 'My first issue', '2020-01-01T17:00:00Z', false, [
       'Exempt'
@@ -819,6 +820,34 @@ test('exempt issue labels will not be marked stale', async () => {
 
   expect(processor.staleIssues.length).toEqual(0);
   expect(processor.closedIssues.length).toEqual(0);
+  expect(processor.removedLabelIssues.length).toEqual(0);
+});
+
+test('exempt issue labels will not be marked stale and will remove the existing stale label', async () => {
+  expect.assertions(3);
+  const opts = {...DefaultProcessorOptions};
+  opts.exemptIssueLabels = 'Exempt';
+
+  const TestIssueList: Issue[] = [
+    generateIssue(1, 'My first issue', '2020-01-01T17:00:00Z', false, [
+      opts.exemptIssueLabels, opts.staleIssueLabel
+    ])
+  ];
+
+  const processor = new IssueProcessor(
+    opts,
+    async () => 'abot',
+    async p => (p == 1 ? TestIssueList : []),
+    async (num: number, dt: string) => [],
+    async (issue: Issue, label: string) => new Date().toDateString()
+  );
+
+  // process our fake issue list
+  await processor.processIssues(1);
+
+  expect(processor.staleIssues.length).toEqual(0);
+  expect(processor.closedIssues.length).toEqual(0);
+  expect(processor.removedLabelIssues.length).toEqual(1);
 });
 
 test('exempt issue labels will not be marked stale (multi issue label with spaces)', async () => {
@@ -1150,7 +1179,7 @@ test('skips stale message on issues when skip-stale-issue-message is set', async
   );
 
   // for sake of testing, mocking private function
-  const markSpy = jest.spyOn(processor as any, 'markStale');
+  const markSpy = jest.spyOn(processor as any, '_markStale');
 
   await processor.processIssues(1);
 
@@ -1195,7 +1224,7 @@ test('skips stale message on prs when skip-stale-pr-message is set', async () =>
   );
 
   // for sake of testing, mocking private function
-  const markSpy = jest.spyOn(processor as any, 'markStale');
+  const markSpy = jest.spyOn(processor as any, '_markStale');
 
   await processor.processIssues(1);
 

src/IssueProcessor.ts

@@ -204,18 +204,7 @@ export class IssueProcessor {
         continue; // don't process locked issues
       }
 
-      if (
-        exemptLabels.some((exemptLabel: string) =>
-          isLabeled(issue, exemptLabel)
-        )
-      ) {
-        issueLogger.info(
-          `Skipping ${issueType} because it has an exempt label`
-        );
-        continue; // don't process exempt issues
-      }
-
-      // does this issue have a stale label?
+      // Does this issue have a stale label?
       let isStale: boolean = isLabeled(issue, staleLabel);
 
       if (isStale) {
@@ -224,6 +213,20 @@ export class IssueProcessor {
         issueLogger.info(`This issue hasn't a stale label`);
       }
 
+      if (
+        exemptLabels.some((exemptLabel: Readonly<string>): boolean =>
+          isLabeled(issue, exemptLabel)
+        )
+      ) {
+        if (isStale) {
+          core.info(`An exempt label was added after the stale label.`);
+          await this._removeStaleLabel(issue, staleLabel);
+        }
+
+        core.info(`Skipping ${issueType} because it has an exempt label`);
+        continue; // don't process exempt issues
+      }
+
       // should this issue be marked stale?
       const shouldBeStale = !IssueProcessor._updatedSince(
         issue.updated_at,