General refactoring

src/api/get-changed-files.ts

@@ -0,0 +1,24 @@
+import * as core from '@actions/core';
+import * as github from '@actions/github';
+import {ClientType} from './types';
+
+export const getChangedFiles = async (
+  client: ClientType,
+  prNumber: number
+): Promise<string[]> => {
+  const listFilesOptions = client.rest.pulls.listFiles.endpoint.merge({
+    owner: github.context.repo.owner,
+    repo: github.context.repo.repo,
+    pull_number: prNumber
+  });
+
+  const listFilesResponse = await client.paginate(listFilesOptions);
+  const changedFiles = listFilesResponse.map((f: any) => f.filename);
+
+  core.debug('found changed files:');
+  for (const file of changedFiles) {
+    core.debug('  ' + file);
+  }
+
+  return changedFiles;
+};