feat: Add a skip_token_revoke input for configuring token revocation (#54)

Fixes #55

Currently, `actions/create-github-app-token` always/unconditionally
revokes the installation access token in a `post` step, at the
completion of the current job. This prevents tokens from being used in
other jobs.

This PR makes this behavior configurable:
- When the `skip-token-revoke` input is not specified (i.e. by default),
the token is revoked in a `post` step (i.e. the current behavior).
- When the `skip-token-revoke` input is set to a truthy value (e.g.
`"true"`[^1]), the token is not revoked in a `post` step.

This PR adds a test for the `skip-token-revoke: "true"` case.

This is configurable in other app token actions, e.g.
[tibdex/github-app-token](https://github.com/tibdex/github-app-token/blob/3eb77c7243b85c65e84acfa93fdbac02fb6bd532/README.md?plain=1#L46-L47)
and
[wow-actions/use-app-token](https://github.com/wow-actions/use-app-token/blob/cd772994fc762f99cf291f308797341327a49b0c/README.md?plain=1#L132).

[^1]: Note that `"false"` is also truthy: `Boolean("false")` is `true`.
If we think that’ll potentially confuse folks, I can require
`skip-token-revoke` to be set explicitly to `"true"`.

Author: smockle

README.md

@@ -145,6 +145,10 @@ jobs:
 > [!NOTE]
 > If `owner` is set and `repositories` is empty, access will be scoped to all repositories in the provided repository owner's installation. If `owner` and `repositories` are empty, access will be scoped to only the current repository.
 
+### `skip_token_revoke`
+
+**Optional:** If truthy, the token will not be revoked when the current job is complete.
+
 ## Outputs
 
 ### `token`
@@ -158,7 +162,7 @@ The action creates an installation access token using [the `POST /app/installati
 1. The token is scoped to the current repository or `repositories` if set.
 2. The token inherits all the installation's permissions.
 3. The token is set as output `token` which can be used in subsequent steps.
-4. The token is revoked in the `post` step of the action, which means it cannot be passed to another job.
+4. Unless the `skip_token_revoke` input is set to a truthy value, the token is revoked in the `post` step of the action, which means it cannot be passed to another job.
 5. The token is masked, it cannot be logged accidentally.
 
 > [!NOTE]

action.yml

@@ -17,6 +17,9 @@ inputs:
   repositories:
     description: "Repositories to install the GitHub App on (defaults to current repository if owner is unset)"
     required: false
+  skip_token_revoke:
+    description: "If truthy, the token will not be revoked when the current job is complete"
+    required: false
 outputs:
   token:
     description: "GitHub installation access token"

dist/main.cjs

@@ -10006,7 +10006,7 @@ var import_core = __toESM(require_core(), 1);
 var import_auth_app = __toESM(require_dist_node12(), 1);
 
 // lib/main.js
-async function main(appId2, privateKey2, owner2, repositories2, core2, createAppAuth2, request2) {
+async function main(appId2, privateKey2, owner2, repositories2, core2, createAppAuth2, request2, skipTokenRevoke2) {
   let parsedOwner = "";
   let parsedRepositoryNames = "";
   if (!owner2 && !repositories2) {
@@ -10082,7 +10082,9 @@ async function main(appId2, privateKey2, owner2, repositories2, core2, createApp
   }
   core2.setSecret(authentication.token);
   core2.setOutput("token", authentication.token);
-  core2.saveState("token", authentication.token);
+  if (!skipTokenRevoke2) {
+    core2.saveState("token", authentication.token);
+  }
 }
 
 // lib/request.js
@@ -10105,6 +10107,7 @@ var appId = import_core.default.getInput("app_id");
 var privateKey = import_core.default.getInput("private_key");
 var owner = import_core.default.getInput("owner");
 var repositories = import_core.default.getInput("repositories");
+var skipTokenRevoke = Boolean(import_core.default.getInput("skip_token_revoke"));
 main(
   appId,
   privateKey,
@@ -10114,7 +10117,8 @@ main(
   import_auth_app.createAppAuth,
   request_default.defaults({
     baseUrl: process.env["GITHUB_API_URL"]
-  })
+  }),
+  skipTokenRevoke
 ).catch((error) => {
   console.error(error);
   import_core.default.setFailed(error.message);

dist/post.cjs

@@ -2973,6 +2973,11 @@ var import_core = __toESM(require_core(), 1);
 
 // lib/post.js
 async function post(core2, request2) {
+  const skipTokenRevoke = Boolean(core2.getInput("skip_token_revoke"));
+  if (skipTokenRevoke) {
+    core2.info("Token revocation was skipped");
+    return;
+  }
   const token = core2.getState("token");
   if (!token) {
     core2.info("Token is not set");

lib/main.js

@@ -8,6 +8,7 @@
  * @param {import("@actions/core")} core
  * @param {import("@octokit/auth-app").createAppAuth} createAppAuth
  * @param {import("@octokit/request").request} request
+ * @param {boolean} skipTokenRevoke
  */
 export async function main(
   appId,
@@ -16,7 +17,8 @@ export async function main(
   repositories,
   core,
   createAppAuth,
-  request
+  request,
+  skipTokenRevoke
 ) {
   let parsedOwner = "";
   let parsedRepositoryNames = "";
@@ -122,5 +124,7 @@ export async function main(
   core.setOutput("token", authentication.token);
 
   // Make token accessible to post function (so we can invalidate it)
-  core.saveState("token", authentication.token);
+  if (!skipTokenRevoke) {
+    core.saveState("token", authentication.token);
+  }
 }

lib/post.js

@@ -5,6 +5,13 @@
  * @param {import("@octokit/request").request} request
  */
 export async function post(core, request) {
+  const skipTokenRevoke = Boolean(core.getInput("skip_token_revoke"));
+
+  if (skipTokenRevoke) {
+    core.info("Token revocation was skipped");
+    return;
+  }
+
   const token = core.getState("token");
 
   if (!token) {

main.js

@@ -19,6 +19,8 @@ const privateKey = core.getInput("private_key");
 const owner = core.getInput("owner");
 const repositories = core.getInput("repositories");
 
+const skipTokenRevoke = Boolean(core.getInput("skip_token_revoke"));
+
 main(
   appId,
   privateKey,
@@ -28,7 +30,8 @@ main(
   createAppAuth,
   request.defaults({
     baseUrl: process.env["GITHUB_API_URL"],
-  })
+  }),
+  skipTokenRevoke
 ).catch((error) => {
   console.error(error);
   core.setFailed(error.message);

tests/README.md

@@ -6,7 +6,7 @@ Add one test file per scenario. You can run them in isolation with:
 node tests/post-token-set.test.js
 ```
 
-All tests are run together in [tests/index.js](index.js), which can be execauted with ava
+All tests are run together in [tests/index.js](index.js), which can be executed with ava
 
 ```
 npx ava tests/index.js

tests/post-token-skipped.test.js

@@ -0,0 +1,29 @@
+import { MockAgent, setGlobalDispatcher } from "undici";
+
+// state variables are set as environment variables with the prefix STATE_
+// https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#sending-values-to-the-pre-and-post-actions
+process.env.STATE_token = "secret123";
+
+// inputs are set as environment variables with the prefix INPUT_
+// https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#example-specifying-inputs
+process.env.INPUT_SKIP_TOKEN_REVOKE = "true";
+
+const mockAgent = new MockAgent();
+
+setGlobalDispatcher(mockAgent);
+
+// Provide the base url to the request
+const mockPool = mockAgent.get("https://api.github.com");
+
+// intercept the request
+mockPool
+  .intercept({
+    path: "/installation/token",
+    method: "DELETE",
+    headers: {
+      authorization: "token secret123",
+    },
+  })
+  .reply(204);
+
+await import("../post.js");

tests/snapshots/index.js.md

@@ -14,6 +14,16 @@ Generated by [AVA](https://avajs.dev).
 
     'Token revoked'
 
+## post-token-skipped.test.js
+
+> stderr
+
+    ''
+
+> stdout
+
+    'Token revocation was skipped'
+
 ## post-token-unset.test.js
 
 > stderr