telemetry for incorrect merge commit (#253)

1 files changed, 108 insertions, 0 deletions

diff --git a/src/ref-helper.ts b/src/ref-helper.ts
index ff256af..f600179 100644
--- a/src/ref-helper.ts
+++ b/src/ref-helper.ts
@@ -1,4 +1,7 @@
+import {URL} from 'url'
 import {IGitCommandManager} from './git-command-manager'
+import * as core from '@actions/core'
+import * as github from '@actions/github'
 
 export interface ICheckoutInfo {
   ref: string
@@ -107,3 +110,108 @@ export function getRefSpec(ref: string, commit: string): string[] {
     return [`+${ref}:${ref}`]
   }
 }
+
+export async function checkCommitInfo(
+  token: string,
+  commitInfo: string,
+  repositoryOwner: string,
+  repositoryName: string,
+  ref: string,
+  commit: string
+): Promise<void> {
+  try {
+    // GHES?
+    if (isGhes()) {
+      return
+    }
+
+    // Auth token?
+    if (!token) {
+      return
+    }
+
+    // Public PR synchronize, for workflow repo?
+    if (
+      fromPayload('repository.private') !== false ||
+      github.context.eventName !== 'pull_request' ||
+      fromPayload('action') !== 'synchronize' ||
+      repositoryOwner !== github.context.repo.owner ||
+      repositoryName !== github.context.repo.repo ||
+      ref !== github.context.ref ||
+      !ref.startsWith('refs/pull/') ||
+      commit !== github.context.sha
+    ) {
+      return
+    }
+
+    // Head SHA
+    const expectedHeadSha = fromPayload('after')
+    if (!expectedHeadSha) {
+      core.debug('Unable to determine head sha')
+      return
+    }
+
+    // Base SHA
+    const expectedBaseSha = fromPayload('pull_request.base.sha')
+    if (!expectedBaseSha) {
+      core.debug('Unable to determine base sha')
+      return
+    }
+
+    // Expected message?
+    const expectedMessage = `Merge ${expectedHeadSha} into ${expectedBaseSha}`
+    if (commitInfo.indexOf(expectedMessage) >= 0) {
+      return
+    }
+
+    // Extract details from message
+    const match = commitInfo.match(/Merge ([0-9a-f]{40}) into ([0-9a-f]{40})/)
+    if (!match) {
+      core.debug('Unexpected message format')
+      return
+    }
+
+    // Post telemetry
+    const actualHeadSha = match[1]
+    if (actualHeadSha !== expectedHeadSha) {
+      core.debug(
+        `Expected head sha ${expectedHeadSha}; actual head sha ${actualHeadSha}`
+      )
+      const octokit = new github.GitHub(token, {
+        userAgent: `actions-checkout-tracepoint/1.0 (code=STALE_MERGE;owner=${repositoryOwner};repo=${repositoryName};pr=${fromPayload(
+          'number'
+        )};run_id=${
+          process.env['GITHUB_RUN_ID']
+        };expected_head_sha=${expectedHeadSha};actual_head_sha=${actualHeadSha})`
+      })
+      await octokit.repos.get({owner: repositoryOwner, repo: repositoryName})
+    }
+  } catch (err) {
+    core.debug(`Error when validating commit info: ${err.stack}`)
+  }
+}
+
+function fromPayload(path: string): any {
+  return select(github.context.payload, path)
+}
+
+function select(obj: any, path: string): any {
+  if (!obj) {
+    return undefined
+  }
+
+  const i = path.indexOf('.')
+  if (i < 0) {
+    return obj[path]
+  }
+
+  const key = path.substr(0, i)
+  return select(obj[key], path.substr(i + 1))
+}
+
+function isGhes(): boolean {
+  const ghUrl = new URL(
+    process.env['GITHUB_SERVER_URL'] || 'https://github.com'
+  )
+  return ghUrl.hostname.toUpperCase() !== 'GITHUB.COM'
+}