Only use a single comment when the action fails

README.md

@@ -6,15 +6,15 @@ This action allows you to fail the build if/unless a certain combination of labe
 
 This action has three required inputs; `labels`, `mode` and `count`
 
-| Name          | Description                                                                                                 | Required | Default             |
-| ------------- | ----------------------------------------------------------------------------------------------------------- | -------- | ------------------- |
-| `labels`      | Comma separated list of labels to match                                                                     | true     |
-| `mode`        | The mode of comparison to use. One of: exactly, minimum, maximum                                            | true     |
-| `count`       | The required number of labels to match                                                                      | true     |
-| `token`       | The GitHub token to use when calling the API                                                                | false    | ${{ github.token }} |
-| `message`     | The message to log and to add to the PR (if add_comment is true). See the README for available placeholders | false    |
-| `add_comment` | Add a comment to the PR if required labels are missing                                                      | false    | false               |
-| `exit_type`   | The exit type of the action. One of: failure, success                                                       | false    |
+| Name          | Description                                                                                                                                                  | Required | Default             |
+| ------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | -------- | ------------------- |
+| `labels`      | Comma separated list of labels to match                                                                                                                      | true     |
+| `mode`        | The mode of comparison to use. One of: exactly, minimum, maximum                                                                                             | true     |
+| `count`       | The required number of labels to match                                                                                                                       | true     |
+| `token`       | The GitHub token to use when calling the API                                                                                                                 | false    | ${{ github.token }} |
+| `message`     | The message to log and to add to the PR (if add_comment is true). See the README for available placeholders                                                  | false    |
+| `add_comment` | Add a comment to the PR if required labels are missing. If a comment already exists, it will be updated. When the action passes, the comment will be deleted | false    | false               |
+| `exit_type`   | The exit type of the action. One of: failure, success                                                                                                        | false    |
 
 This action calls the GitHub API to fetch labels for a PR rather than reading `event.json`. This allows the action to run as intended when an earlier step adds a label. It will use `github.token` by default, and you can set the `token` input to provide alternative authentication.
 
@@ -31,10 +31,10 @@ jobs:
   label:
     runs-on: ubuntu-latest
     permissions:
-      issues: read
-      pull-requests: read
+      issues: write
+      pull-requests: write
     steps:
-      - uses: mheap/github-action-required-labels@v3
+      - uses: mheap/github-action-required-labels@v4
         with:
           mode: exactly
           count: 1
@@ -44,7 +44,7 @@ jobs:
 ### Prevent merging if a label exists
 
 ```yaml
-- uses: mheap/github-action-required-labels@v3
+- uses: mheap/github-action-required-labels@v4
   with:
     mode: exactly
     count: 0
@@ -58,20 +58,22 @@ You can choose to add a comment to the PR when the action fails. The default for
 > Label error. Requires {{ errorString }} {{ count }} of: {{ provided }}. Found: {{ applied }}
 
 ```yaml
-- uses: mheap/github-action-required-labels@v3
+- uses: mheap/github-action-required-labels@v4
   with:
     mode: exactly
     count: 1
     labels: "semver:patch, semver:minor, semver:major"
     add_comment: true
 ```
 
+If a comment already exists, it will be updated. When the action passes, the comment will be deleted.
+
 ### Customising the failure message / comment
 
 You can also customise the message used by providing the `message` input:
 
 ```yaml
-- uses: mheap/github-action-required-labels@v3
+- uses: mheap/github-action-required-labels@v4
   with:
     mode: exactly
     count: 1
@@ -93,7 +95,7 @@ The following tokens are available for use in custom messages:
 ### Require multiple labels
 
 ```yaml
-- uses: mheap/github-action-required-labels@v3
+- uses: mheap/github-action-required-labels@v4
   with:
     mode: minimum
     count: 2
@@ -105,7 +107,7 @@ The following tokens are available for use in custom messages:
 You can set `exit_type` to success then inspect `outputs.status` to see if the action passed or failed. This is useful when you want to perform additional actions if a label is not present, but not fail the entire build.
 
 ```yaml
-- uses: mheap/github-action-required-labels@v3
+- uses: mheap/github-action-required-labels@v4
   with:
     mode: minimum
     count: 2
@@ -126,13 +128,13 @@ jobs:
   label:
     runs-on: ubuntu-latest
     permissions:
-      issues: read
-      pull-requests: read
+      issues: write
+      pull-requests: write
     outputs:
       status: ${{ steps.check-labels.outputs.status }}
     steps:
       - id: check-labels
-        uses: mheap/github-action-required-labels@v3
+        uses: mheap/github-action-required-labels@v4
         with:
           mode: exactly
           count: 1

index.js

@@ -1,6 +1,7 @@
 const core = require("@actions/core");
 const github = require("@actions/github");
 
+const matchToken = `<!-- reqlabelmessage -->`;
 async function action() {
   try {
     const token = core.getInput("token", { required: true });
@@ -84,6 +85,24 @@ async function action() {
       return;
     }
 
+    // Remove the comment if it exists
+    if (shouldAddComment) {
+      const { data: existing } = await octokit.rest.issues.listComments({
+        ...github.context.repo,
+        issue_number: github.context.issue.number,
+      });
+
+      const generatedComment = existing.find((c) =>
+        c.body.includes(matchToken)
+      );
+      if (generatedComment) {
+        await octokit.rest.issues.deleteComment({
+          ...github.context.repo,
+          comment_id: generatedComment.id,
+        });
+      }
+    }
+
     core.setOutput("status", "success");
   } catch (e) {
     core.setFailed(e.message);
@@ -98,11 +117,27 @@ function tmpl(t, o) {
 
 async function exitWithError(exitType, octokit, shouldAddComment, message) {
   if (shouldAddComment) {
-    await octokit.rest.issues.createComment({
+    // Is there an existing comment?
+    const { data: existing } = await octokit.rest.issues.listComments({
       ...github.context.repo,
       issue_number: github.context.issue.number,
-      body: message,
     });
+
+    const generatedComment = existing.find((c) => c.body.includes(matchToken));
+
+    const params = {
+      ...github.context.repo,
+      issue_number: github.context.issue.number,
+      body: `${matchToken}${message}`,
+    };
+
+    // If so, update it
+    let method = "createComment";
+    if (generatedComment) {
+      method = "updateComment";
+      params.comment_id = generatedComment.id;
+    }
+    await octokit.rest.issues[method](params);
   }
 
   core.setOutput("status", "failure");

index.test.js

@@ -6,6 +6,8 @@ const mockedEnv = require("mocked-env");
 const nock = require("nock");
 nock.disableNetConnect();
 
+const matchToken = `<!-- reqlabelmessage -->`;
+
 describe("Required Labels", () => {
   let restore;
   let restoreTest;
@@ -90,14 +92,35 @@ describe("Required Labels", () => {
 
       mockLabels(["bug"]);
 
+      mockListComments([]);
+
       nock("https://api.github.com")
         .post("/repos/mheap/missing-repo/issues/28/comments", {
-          body: "Label error. Requires exactly 1 of: enhancement. Found: bug",
+          body: `${matchToken}Label error. Requires exactly 1 of: enhancement. Found: bug`,
         })
         .reply(201);
 
       await action();
     });
+
+    it("deletes a comment when passing", async () => {
+      restoreTest = mockPr({
+        INPUT_LABELS: "bug",
+        INPUT_MODE: "exactly",
+        INPUT_COUNT: "1",
+        INPUT_ADD_COMMENT: "true",
+        GITHUB_TOKEN: "mock-token-here-abc",
+      });
+
+      mockLabels(["bug"]);
+      mockListComments([{ id: "12345", body: `${matchToken}This` }]);
+
+      nock("https://api.github.com")
+        .delete("/repos/mheap/missing-repo/issues/comments/12345")
+        .reply(200);
+
+      await action();
+    });
   });
 
   describe("success", () => {
@@ -369,9 +392,58 @@ describe("Required Labels", () => {
 
       mockLabels(["enhancement", "bug"]);
 
+      mockListComments([]);
+
+      nock("https://api.github.com")
+        .post("/repos/mheap/missing-repo/issues/28/comments", {
+          body: `${matchToken}This is a static comment`,
+        })
+        .reply(201);
+
+      await action();
+    });
+
+    it("updates an existing comment when one is found", async () => {
+      restoreTest = mockPr({
+        GITHUB_TOKEN: "abc123",
+        INPUT_LABELS: "enhancement,bug",
+        INPUT_MODE: "exactly",
+        INPUT_COUNT: "1",
+        INPUT_ADD_COMMENT: "true",
+        INPUT_MESSAGE: "This is a static comment",
+      });
+
+      mockLabels(["enhancement", "bug"]);
+
+      mockListComments([{ id: "12345", body: `${matchToken}This` }]);
+
+      nock("https://api.github.com")
+        .patch("/repos/mheap/missing-repo/issues/comments/12345", {
+          issue_number: 28,
+          body: `${matchToken}This is a static comment`,
+        })
+        .reply(200);
+
+      await action();
+    });
+
+    it("creates when comments exist but don't match", async () => {
+      restoreTest = mockPr({
+        GITHUB_TOKEN: "abc123",
+        INPUT_LABELS: "enhancement,bug",
+        INPUT_MODE: "exactly",
+        INPUT_COUNT: "1",
+        INPUT_ADD_COMMENT: "true",
+        INPUT_MESSAGE: "This is a static comment",
+      });
+
+      mockLabels(["enhancement", "bug"]);
+
+      mockListComments([{ id: "12345", body: `No Match` }]);
+
       nock("https://api.github.com")
         .post("/repos/mheap/missing-repo/issues/28/comments", {
-          body: "This is a static comment",
+          body: `${matchToken}This is a static comment`,
         })
         .reply(201);
 
@@ -392,9 +464,10 @@ describe("Required Labels", () => {
 
       mockLabels(["enhancement", "bug"]);
 
+      mockListComments([]);
       nock("https://api.github.com")
         .post("/repos/mheap/missing-repo/issues/28/comments", {
-          body: "Mode: exactly, Count: 1, Error String: exactly, Provided: enhancement, bug, Applied: enhancement, bug",
+          body: `${matchToken}Mode: exactly, Count: 1, Error String: exactly, Provided: enhancement, bug, Applied: enhancement, bug`,
         })
         .reply(201);
 
@@ -428,6 +501,17 @@ function mockLabels(labels) {
     );
 }
 
+function mockListComments(comments) {
+  nock("https://api.github.com")
+    .get("/repos/mheap/missing-repo/issues/28/comments")
+    .reply(
+      200,
+      comments.map((c) => {
+        return { body: c.body, id: c.id };
+      })
+    );
+}
+
 function mockEvent(eventName, mockPayload, additionalParams = {}) {
   github.context.payload = mockPayload;