chore: fix circle-env for contributor PRs

scripts/circle-env.js

@@ -21,6 +21,10 @@ async function checkCanaries () {
 
   const circleEnv = await readCircleEnv()
 
+  if (Object.keys(circleEnv).length === 0) {
+    return console.warn('CircleCI env empty, assuming this is a contributor PR. Not checking for canary variables.')
+  }
+
   if (!circleEnv.MAIN_CANARY) throw new Error('Missing MAIN_CANARY.')
 
   if (!circleEnv.CONTEXT_CANARY) throw new Error('Missing CONTEXT_CANARY. Does this job have the test-runner:env-canary context?')
@@ -36,7 +40,12 @@ async function readCircleEnv () {
     // if this starts failing, try SSHing into a CircleCI job and see what changed in the $CIRCLE_INTERNAL_CONFIG file's schema
     const circleEnv = taskData['Dispatched']['TaskInfo']['Environment']
 
-    if (!circleEnv || !Object.keys(circleEnv).length) throw new Error('An empty Environment object was found.')
+    if (!circleEnv) throw new Error('No Environment object was found.')
+
+    // last-ditch effort to check that an empty circle env is accurately reflecting process.env (external PRs)
+    if (process.env.CACHE_VERSION && Object.keys(circleEnv).length === 0) {
+      throw new Error('CACHE_VERSION is set, but circleEnv is empty')
+    }
 
     return circleEnv
   } catch (err) {

scripts/unit/circle-env-spec.js

@@ -12,22 +12,49 @@ describe('circle-env', () => {
   })
 
   beforeEach(() => {
+    delete process.env.CACHE_VERSION
     process.env.CI = 'true'
     process.env.CIRCLE_INTERNAL_CONFIG = '/foo.json'
   })
 
-  it('fails with missing canaries', async () => {
-    sinon.stub(fs, 'readFile')
-    .withArgs('/foo.json').resolves(JSON.stringify({
-      Dispatched: { TaskInfo: { Environment: { somekey: 'someval' } } },
-    }))
+  context('with missing canaries', () => {
+    it('fails', async () => {
+      sinon.stub(fs, 'readFile')
+      .withArgs('/foo.json').resolves(JSON.stringify({
+        Dispatched: { TaskInfo: { Environment: { somekey: 'someval' } } },
+      }))
+
+      try {
+        await _checkCanaries()
+        throw new Error('should not reach')
+      } catch (err) {
+        expect(err.message).to.include('Missing MAIN_CANARY')
+      }
+    })
+
+    context('with no circleEnv', () => {
+      beforeEach(() => {
+        sinon.stub(fs, 'readFile')
+        .withArgs('/foo.json').resolves(JSON.stringify({
+          Dispatched: { TaskInfo: { Environment: {} } },
+        }))
+      })
+
+      it('passes', async () => {
+        await _checkCanaries()
+      })
+
+      it('fails if CACHE_VERSION does exist', async () => {
+        process.env.CACHE_VERSION = 'foo'
 
-    try {
-      await _checkCanaries()
-      throw new Error('should not reach')
-    } catch (err) {
-      expect(err.message).to.include('Missing MAIN_CANARY')
-    }
+        try {
+          await _checkCanaries()
+          throw new Error('should not reach')
+        } catch (err) {
+          expect(err.message).to.include('CACHE_VERSION is set, but circleEnv is empty')
+        }
+      })
+    })
   })
 
   it('passes with canaries', async () => {