Refactor issue processor (#45)

* Refctor into an issue processor, add debug mode
* Move processor to use its own types so testing is easier
* Add more tests

src/main.ts

@@ -1,164 +1,19 @@
 import * as core from '@actions/core';
-import * as github from '@actions/github';
-import {Octokit} from '@octokit/rest';
-
-type Issue = Octokit.IssuesListForRepoResponseItem;
-type IssueLabel = Octokit.IssuesListForRepoResponseItemLabelsItem;
-
-interface Args {
-  repoToken: string;
-  staleIssueMessage: string;
-  stalePrMessage: string;
-  daysBeforeStale: number;
-  daysBeforeClose: number;
-  staleIssueLabel: string;
-  exemptIssueLabels: string;
-  stalePrLabel: string;
-  exemptPrLabels: string;
-  onlyLabels: string;
-  operationsPerRun: number;
-}
+import {IssueProcessor, IssueProcessorOptions} from './IssueProcessor';
 
 async function run(): Promise<void> {
   try {
     const args = getAndValidateArgs();
 
-    const client = new github.GitHub(args.repoToken);
-    await processIssues(client, args, args.operationsPerRun);
+    const processor: IssueProcessor = new IssueProcessor(args);
+    await processor.processIssues();
   } catch (error) {
     core.error(error);
     core.setFailed(error.message);
   }
 }
 
-async function processIssues(
-  client: github.GitHub,
-  args: Args,
-  operationsLeft: number,
-  page: number = 1
-): Promise<number> {
-  const issues = await client.issues.listForRepo({
-    owner: github.context.repo.owner,
-    repo: github.context.repo.repo,
-    state: 'open',
-    labels: args.onlyLabels,
-    per_page: 100,
-    page
-  });
-
-  operationsLeft -= 1;
-
-  if (issues.data.length === 0 || operationsLeft === 0) {
-    return operationsLeft;
-  }
-
-  for (const issue of issues.data.values()) {
-    core.debug(`found issue: ${issue.title} last updated ${issue.updated_at}`);
-    const isPr = !!issue.pull_request;
-
-    const staleMessage = isPr ? args.stalePrMessage : args.staleIssueMessage;
-    if (!staleMessage) {
-      core.debug(`skipping ${isPr ? 'pr' : 'issue'} due to empty message`);
-      continue;
-    }
-
-    const staleLabel = isPr ? args.stalePrLabel : args.staleIssueLabel;
-    const exemptLabels = parseCommaSeparatedString(
-      isPr ? args.exemptPrLabels : args.exemptIssueLabels
-    );
-
-    if (exemptLabels.some(exemptLabel => isLabeled(issue, exemptLabel))) {
-      continue;
-    } else if (isLabeled(issue, staleLabel)) {
-      if (
-        args.daysBeforeClose >= 0 &&
-        wasLastUpdatedBefore(issue, args.daysBeforeClose)
-      ) {
-        operationsLeft -= await closeIssue(client, issue);
-      } else {
-        continue;
-      }
-    } else if (wasLastUpdatedBefore(issue, args.daysBeforeStale)) {
-      operationsLeft -= await markStale(
-        client,
-        issue,
-        staleMessage,
-        staleLabel
-      );
-    }
-
-    if (operationsLeft <= 0) {
-      core.warning(
-        `performed ${args.operationsPerRun} operations, exiting to avoid rate limit`
-      );
-      return 0;
-    }
-  }
-  return await processIssues(client, args, operationsLeft, page + 1);
-}
-
-function isLabeled(issue: Issue, label: string): boolean {
-  const labelComparer: (l: IssueLabel) => boolean = l =>
-    label.localeCompare(l.name, undefined, {sensitivity: 'accent'}) === 0;
-  return issue.labels.filter(labelComparer).length > 0;
-}
-
-function wasLastUpdatedBefore(issue: Issue, num_days: number): boolean {
-  const daysInMillis = 1000 * 60 * 60 * 24 * num_days;
-  const millisSinceLastUpdated =
-    new Date().getTime() - new Date(issue.updated_at).getTime();
-  return millisSinceLastUpdated >= daysInMillis;
-}
-
-async function markStale(
-  client: github.GitHub,
-  issue: Issue,
-  staleMessage: string,
-  staleLabel: string
-): Promise<number> {
-  core.debug(`marking issue${issue.title} as stale`);
-
-  await client.issues.createComment({
-    owner: github.context.repo.owner,
-    repo: github.context.repo.repo,
-    issue_number: issue.number,
-    body: staleMessage
-  });
-
-  await client.issues.addLabels({
-    owner: github.context.repo.owner,
-    repo: github.context.repo.repo,
-    issue_number: issue.number,
-    labels: [staleLabel]
-  });
-
-  return 2; // operations performed
-}
-
-async function closeIssue(
-  client: github.GitHub,
-  issue: Issue
-): Promise<number> {
-  core.debug(`closing issue ${issue.title} for being stale`);
-
-  await client.issues.update({
-    owner: github.context.repo.owner,
-    repo: github.context.repo.repo,
-    issue_number: issue.number,
-    state: 'closed'
-  });
-
-  return 1; // operations performed
-}
-
-function parseCommaSeparatedString(s: string): string[] {
-  // String.prototype.split defaults to [''] when called on an empty string
-  // In this case, we'd prefer to just return an empty array indicating no labels
-  if (!s.length) return [];
-  return s.split(',');
-}
-
-function getAndValidateArgs(): Args {
+function getAndValidateArgs(): IssueProcessorOptions {
   const args = {
     repoToken: core.getInput('repo-token', {required: true}),
     staleIssueMessage: core.getInput('stale-issue-message'),
@@ -176,7 +31,8 @@ function getAndValidateArgs(): Args {
     onlyLabels: core.getInput('only-labels'),
     operationsPerRun: parseInt(
       core.getInput('operations-per-run', {required: true})
-    )
+    ),
+    debugOnly: core.getInput('debug-only') === 'true'
   };
 
   for (const numberInput of [