fix: make GITHUB_REF env var optional

Author: billputer

index.js

@@ -28,9 +28,9 @@ async function assumeRole(params) {
       "Missing required input when assuming a Role."
   );
 
-  const {GITHUB_REPOSITORY, GITHUB_WORKFLOW, GITHUB_ACTION, GITHUB_ACTOR, GITHUB_REF, GITHUB_SHA} = process.env;
+  const {GITHUB_REPOSITORY, GITHUB_WORKFLOW, GITHUB_ACTION, GITHUB_ACTOR, GITHUB_SHA} = process.env;
   assert(
-      [GITHUB_REPOSITORY, GITHUB_WORKFLOW, GITHUB_ACTION, GITHUB_ACTOR, GITHUB_REF, GITHUB_SHA].every(isDefined),
+      [GITHUB_REPOSITORY, GITHUB_WORKFLOW, GITHUB_ACTION, GITHUB_ACTOR, GITHUB_SHA].every(isDefined),
       'Missing required environment value. Are you running in GitHub Actions?'
   );
 
@@ -52,11 +52,14 @@ async function assumeRole(params) {
       {Key: 'Workflow', Value: sanitizeGithubWorkflowName(GITHUB_WORKFLOW)},
       {Key: 'Action', Value: GITHUB_ACTION},
       {Key: 'Actor', Value: sanitizeGithubActor(GITHUB_ACTOR)},
-      {Key: 'Branch', Value: GITHUB_REF},
       {Key: 'Commit', Value: GITHUB_SHA},
     ]
   };
 
+  if (isDefined(process.env.GITHUB_REF)) {
+    assumeRoleRequest.Tags.push({Key: 'Branch', Value: process.env.GITHUB_REF});
+  }
+
   if (roleExternalId) {
     assumeRoleRequest.ExternalId = roleExternalId;
   }

index.test.js

@@ -22,8 +22,8 @@ const ENVIRONMENT_VARIABLE_OVERRIDES = {
     GITHUB_WORKFLOW: 'MY-WORKFLOW-ID',
     GITHUB_ACTION: 'MY-ACTION-NAME',
     GITHUB_ACTOR: 'MY-USERNAME[bot]',
-    GITHUB_REF: 'MY-BRANCH',
     GITHUB_SHA: 'MY-COMMIT-ID',
+    GITHUB_REF: 'MY-BRANCH',
 };
 const GITHUB_ACTOR_SANITIZED = 'MY-USERNAME_bot_'
 
@@ -142,6 +142,26 @@ describe('Configure AWS Credentials', () => {
         expect(core.setSecret).toHaveBeenCalledWith(FAKE_ACCOUNT_ID);
     });
 
+    test('action fails when github env vars are not set', async () => {
+        process.env.SHOW_STACK_TRACE = 'false';
+        core.getInput = jest
+            .fn()
+            .mockImplementation(mockGetInput(ASSUME_ROLE_INPUTS));
+        delete process.env.GITHUB_SHA;
+
+        await run();
+        expect(core.setFailed).toHaveBeenCalledWith('Missing required environment value. Are you running in GitHub Actions?');
+    });
+
+    test('action does not require GITHUB_REF env var', async () => {
+        core.getInput = jest
+            .fn()
+            .mockImplementation(mockGetInput(ASSUME_ROLE_INPUTS));
+        delete process.env.GITHUB_REF;
+
+        await run();
+    });
+
     test('hosted runners can pull creds from a self-hosted environment', async () => {
         const mockInputs = {'aws-region': FAKE_REGION};
         core.getInput = jest
@@ -402,8 +422,8 @@ describe('Configure AWS Credentials', () => {
                 {Key: 'Workflow', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_WORKFLOW},
                 {Key: 'Action', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_ACTION},
                 {Key: 'Actor', Value: GITHUB_ACTOR_SANITIZED},
-                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
                 {Key: 'Commit', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_SHA},
+                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
             ]
         })
     });
@@ -424,8 +444,8 @@ describe('Configure AWS Credentials', () => {
                 {Key: 'Workflow', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_WORKFLOW},
                 {Key: 'Action', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_ACTION},
                 {Key: 'Actor', Value: GITHUB_ACTOR_SANITIZED},
-                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
                 {Key: 'Commit', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_SHA},
+                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
             ]
         })
     });
@@ -446,8 +466,8 @@ describe('Configure AWS Credentials', () => {
                 {Key: 'Workflow', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_WORKFLOW},
                 {Key: 'Action', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_ACTION},
                 {Key: 'Actor', Value: GITHUB_ACTOR_SANITIZED},
-                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
                 {Key: 'Commit', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_SHA},
+                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
             ]
         })
     });
@@ -468,8 +488,8 @@ describe('Configure AWS Credentials', () => {
                 {Key: 'Workflow', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_WORKFLOW},
                 {Key: 'Action', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_ACTION},
                 {Key: 'Actor', Value: GITHUB_ACTOR_SANITIZED},
-                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
                 {Key: 'Commit', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_SHA},
+                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
             ]
         })
     });
@@ -490,8 +510,8 @@ describe('Configure AWS Credentials', () => {
                 {Key: 'Workflow', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_WORKFLOW},
                 {Key: 'Action', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_ACTION},
                 {Key: 'Actor', Value: GITHUB_ACTOR_SANITIZED},
-                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
                 {Key: 'Commit', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_SHA},
+                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
             ],
             ExternalId: 'abcdef'
         })
@@ -517,8 +537,8 @@ describe('Configure AWS Credentials', () => {
                 {Key: 'Workflow', Value: sanitizedWorkflowName},
                 {Key: 'Action', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_ACTION},
                 {Key: 'Actor', Value: GITHUB_ACTOR_SANITIZED},
-                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
                 {Key: 'Commit', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_SHA},
+                {Key: 'Branch', Value: ENVIRONMENT_VARIABLE_OVERRIDES.GITHUB_REF},
             ]
         })
     });