feat: support discussion_comment event

README.md

@@ -63,9 +63,13 @@ jobs:
 
       # Only run if `steps.<id>.outputs.continue` is "true".
       # This indicates that `knowledge-work` successfully parsed the command and the subsequent steps should continue.
+      # IssueOps params are passed through `env:` and referenced as shell variables to avoid
+      # GitHub Actions expression injection from attacker-controlled comment content.
       - name: Greet
         if: ${{ steps.command.outputs.continue == 'true' }}
-        run: echo "Hi ${{ fromJSON(steps.command.outputs.params).name }} !"
+        env:
+          NAME: ${{ fromJSON(steps.command.outputs.params).name }}
+        run: echo "Hi $NAME !"
 
       # Add other steps necessary for IssueOps...
 ```
@@ -164,10 +168,10 @@ Supports null in JSON format.
 
 <!-- gha-inputs-start -->
 
-| ID                 | Required           | Default              | Description                                                                                       |
-| :----------------- | :----------------- | :------------------- | :------------------------------------------------------------------------------------------------ |
-| `command`          | :white_check_mark: | n/a                  | The name of the command to be used in IssueOps, which can be specified as a comma-separated list. |
-| `allowed_contexts` |                    | `issue,pull_request` | The comment contexts that trigger the IssueOps command, specified as a comma-separated list.      |
+| ID                 | Required           | Default                         | Description                                                                                                                                               |
+| :----------------- | :----------------- | :------------------------------ | :-------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `command`          | :white_check_mark: | n/a                             | The name of the command to be used in IssueOps, which can be specified as a comma-separated list.                                                         |
+| `allowed_contexts` |                    | `issue,pull_request,discussion` | The comment contexts that trigger the IssueOps command, specified as a comma-separated list. Allowed values: `"issue"`, `"pull_request"`, `"discussion"`. |
 
 <!-- gha-inputs-end -->
 
@@ -182,8 +186,8 @@ Supports null in JSON format.
 | `comment_id`   | The ID of the comment that triggered this action.                                                                                                                                    |
 | `actor`        | The GitHub handle of the actor who executed the IssueOps command.                                                                                                                    |
 | `issue_number` | [Deprecated] The issue number of the comment that triggered this action. Use `number` instead. This output will be removed in the next major release.                                |
-| `number`       | The number of the issue or pull request that triggered this action.                                                                                                                  |
-| `context`      | The context that triggered this action. One of `"issue"` or `"pull_request"`.                                                                                                        |
+| `number`       | The number of the issue, pull request, or discussion that triggered this action.                                                                                                     |
+| `context`      | The context that triggered this action. One of `"issue"`, `"pull_request"`, or `"discussion"`.                                                                                       |
 | `command`      | The command of the triggered IssueOps command.                                                                                                                                       |
 
 <!-- gha-outputs-end -->
@@ -192,6 +196,40 @@ Supports null in JSON format.
 
 A section introducing tips for implementing IssueOps commands.
 
+### Triggering from GitHub Discussions
+
+`command-action` also handles GitHub Discussions when the workflow is triggered by the `discussion_comment` event. The same parsing logic applies — the only differences are that `outputs.context` becomes `"discussion"` and `outputs.issue_number` is not emitted (use `outputs.number` instead).
+
+```yaml
+name: 'Greet DEMO (Discussions)'
+
+on:
+  discussion_comment:
+    types: [created]
+
+permissions:
+  contents: read
+  discussions: write # only required if your follow-up step writes back to the discussion (e.g. reactions via GraphQL)
+
+jobs:
+  demo:
+    runs-on: ubuntu-latest
+    steps:
+      - id: command
+        uses: knowledge-work/command-action@v1
+        with:
+          command: 'greet'
+      - if: ${{ steps.command.outputs.continue == 'true' }}
+        env:
+          NAME: ${{ fromJSON(steps.command.outputs.params).name }}
+        run: echo "Hi $NAME !"
+```
+
+> [!warning]
+> Discussion / Issue / PR comments are attacker-controlled. Pass IssueOps params via `env:` and reference them as shell variables (`"$NAME"`) instead of interpolating `${{ ... }}` directly into a `run:` script. See [GitHub Actions security hardening](https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-an-intermediate-environment-variable) for details.
+
+To restrict the action to discussions only (or to issues / pull requests only), use the [`allowed_contexts`](#inbox_tray-inputs) input — for example `allowed_contexts: 'discussion'`.
+
 ### Reacting to the comment
 
 You can use [actions/github-script](https://github.com/actions/github-script) to add a reaction to the comment that triggered the IssueOps command.

action.yaml

@@ -10,8 +10,8 @@ inputs:
     description: 'The name of the command to be used in IssueOps, which can be specified as a comma-separated list.'
     required: true
   allowed_contexts:
-    description: 'The comment contexts that trigger the IssueOps command, specified as a comma-separated list.'
-    default: 'issue,pull_request'
+    description: 'The comment contexts that trigger the IssueOps command, specified as a comma-separated list. Allowed values: `"issue"`, `"pull_request"`, `"discussion"`.'
+    default: 'issue,pull_request,discussion'
 
 outputs:
   continue:
@@ -25,9 +25,9 @@ outputs:
   issue_number:
     description: '[Deprecated] The issue number of the comment that triggered this action. Use `number` instead. This output will be removed in the next major release.'
   number:
-    description: 'The number of the issue or pull request that triggered this action.'
+    description: 'The number of the issue, pull request, or discussion that triggered this action.'
   context:
-    description: 'The context that triggered this action. One of `"issue"` or `"pull_request"`.'
+    description: 'The context that triggered this action. One of `"issue"`, `"pull_request"`, or `"discussion"`.'
   command:
     description: 'The command of the triggered IssueOps command.'
 

dist/index.js

@@ -38080,53 +38080,62 @@ const str2array = (input) => input
 
 
 
-const validContexts = new Set(['issue', 'pull_request']);
-const isValidContext = (inputs, isPr) => {
-    if (github_context.eventName !== 'issue_comment') {
-        core/* warning */.$e(`This action only supports the "issue_comment" event, but received "${github_context.eventName}".`);
-        return false;
+const validContexts = new Set(['issue', 'pull_request', 'discussion']);
+const resolveCommentContext = () => {
+    if (github_context.eventName === 'issue_comment') {
+        const isPr = github_context.payload.issue?.['pull_request'] != null;
+        return {
+            kind: isPr ? 'pull_request' : 'issue',
+            number: github_context.payload.issue.number,
+            commentId: github_context.payload.comment.id,
+            actor: github_context.payload.comment['user'].login,
+        };
+    }
+    if (github_context.eventName === 'discussion_comment') {
+        const discussion = github_context.payload['discussion'];
+        return {
+            kind: 'discussion',
+            number: discussion.number,
+            commentId: github_context.payload.comment.id,
+            actor: github_context.payload.comment['user'].login,
+        };
     }
+    return null;
+};
+const isValidContext = (inputs, kind) => {
     const allowedContexts = str2array(inputs.allowed_contexts);
     const invalidContexts = allowedContexts.filter((c) => !validContexts.has(c));
     if (invalidContexts.length > 0) {
-        const list = [...validContexts].map((c) => `"${c}"`).join(' and ');
+        const list = [...validContexts].map((c) => `"${c}"`).join(', ');
         core/* warning */.$e(`The "allowed_contexts" must be a comma-separated string of ${list}, but received "${invalidContexts.join(',')}".`);
         return false;
     }
-    if (allowedContexts.length === 1) {
-        switch (allowedContexts[0]) {
-            case 'issue': {
-                if (isPr) {
-                    core/* info */.pq(`💡The 'issue' context is not allowed for pull requests.`);
-                    return false;
-                }
-                break;
-            }
-            case 'pull_request': {
-                if (!isPr) {
-                    core/* info */.pq(`💡The 'pull_request' context is not allowed for issues.`);
-                    return false;
-                }
-                break;
-            }
-        }
+    if (!allowedContexts.includes(kind)) {
+        core/* info */.pq(`💡The current context "${kind}" is not in allowed_contexts (${allowedContexts.join(',')}).`);
+        return false;
     }
     return true;
 };
 const run = async () => {
     const inputs = getInputs();
     core/* debug */.Yz(`inputs: ${JSON.stringify(inputs)}`);
-    const isPr = github_context?.payload?.issue?.['pull_request'] != null;
-    if (!isValidContext(inputs, isPr)) {
+    const ctx = resolveCommentContext();
+    if (ctx === null) {
+        core/* warning */.$e(`This action only supports the "issue_comment" or "discussion_comment" event, but received "${github_context.eventName}".`);
         core/* setOutput */.uH('continue', 'false');
         return 0;
     }
-    const issueNumber = github_context.payload.issue.number;
-    core/* setOutput */.uH('issue_number', issueNumber);
-    core/* setOutput */.uH('number', issueNumber);
-    core/* setOutput */.uH('context', isPr ? 'pull_request' : 'issue');
-    core/* setOutput */.uH('comment_id', github_context.payload.comment.id);
-    core/* setOutput */.uH('actor', github_context.payload.comment['user'].login);
+    if (!isValidContext(inputs, ctx.kind)) {
+        core/* setOutput */.uH('continue', 'false');
+        return 0;
+    }
+    core/* setOutput */.uH('number', ctx.number);
+    core/* setOutput */.uH('context', ctx.kind);
+    core/* setOutput */.uH('comment_id', ctx.commentId);
+    core/* setOutput */.uH('actor', ctx.actor);
+    if (ctx.kind !== 'discussion') {
+        core/* setOutput */.uH('issue_number', ctx.number);
+    }
     const commands = str2array(inputs.command);
     const body = (github_context.payload.comment?.['body'] ?? '');
     const result = parse_parse(body);

src/main.test.ts

@@ -92,4 +92,78 @@ test('invalid context emits only continue=false and never emits number / context
   expect(outputFor('number')).toBeUndefined();
   expect(outputFor('context')).toBeUndefined();
   expect(outputFor('issue_number')).toBeUndefined();
+  expect(mocks.warning).toHaveBeenCalled();
+  const warningMessage = mocks.warning.mock.calls[0]?.[0] as string;
+  expect(warningMessage).toContain('issue_comment');
+  expect(warningMessage).toContain('discussion_comment');
+});
+
+test('discussion context emits number and context="discussion" without issue_number', async () => {
+  mocks.inputs['allowed_contexts'] = 'issue,pull_request,discussion';
+  mocks.context.eventName = 'discussion_comment';
+  mocks.context.payload = {
+    discussion: { number: 7 },
+    comment: { id: 4004, body: '.foo', user: { login: 'carol' } },
+  };
+
+  await run();
+
+  expect(outputFor('number')).toBe(7);
+  expect(outputFor('context')).toBe('discussion');
+  expect(outputFor('comment_id')).toBe(4004);
+  expect(outputFor('actor')).toBe('carol');
+  expect(outputFor('issue_number')).toBeUndefined();
+  expect(outputFor('continue')).toBe('true');
+});
+
+test('allowed_contexts="issue" rejects a discussion_comment via the filter', async () => {
+  mocks.inputs['allowed_contexts'] = 'issue';
+  mocks.context.eventName = 'discussion_comment';
+  mocks.context.payload = {
+    discussion: { number: 7 },
+    comment: { id: 4004, body: '.foo', user: { login: 'carol' } },
+  };
+
+  await run();
+
+  expect(outputFor('continue')).toBe('false');
+  expect(outputFor('number')).toBeUndefined();
+  expect(outputFor('context')).toBeUndefined();
+  expect(outputFor('issue_number')).toBeUndefined();
+  expect(mocks.info).toHaveBeenCalled();
+});
+
+test('allowed_contexts="discussion" accepts a discussion_comment (single-context positive)', async () => {
+  mocks.inputs['allowed_contexts'] = 'discussion';
+  mocks.context.eventName = 'discussion_comment';
+  mocks.context.payload = {
+    discussion: { number: 7 },
+    comment: { id: 4004, body: '.foo', user: { login: 'carol' } },
+  };
+
+  await run();
+
+  expect(outputFor('number')).toBe(7);
+  expect(outputFor('context')).toBe('discussion');
+  expect(outputFor('issue_number')).toBeUndefined();
+  expect(outputFor('continue')).toBe('true');
+  const rejectionInfoCalls = mocks.info.mock.calls.filter(([msg]) =>
+    typeof msg === 'string' ? msg.includes('not in allowed_contexts') : false,
+  );
+  expect(rejectionInfoCalls).toHaveLength(0);
+});
+
+test('allowed_contexts="discussion" rejects an issue_comment (heterogeneous single-context)', async () => {
+  mocks.inputs['allowed_contexts'] = 'discussion';
+  mocks.context.eventName = 'issue_comment';
+  mocks.context.payload = {
+    issue: { number: 42 },
+    comment: { id: 1001, body: '.foo', user: { login: 'alice' } },
+  };
+
+  await run();
+
+  expect(outputFor('continue')).toBe('false');
+  expect(outputFor('context')).toBeUndefined();
+  expect(outputFor('number')).toBeUndefined();
 });

src/main.ts

@@ -4,41 +4,53 @@ import { type Inputs, getInputs } from './inputs.js';
 import { parse } from './parse.js';
 import { str2array } from './utils.js';
 
-const validContexts = new Set(['issue', 'pull_request']);
+type CommentKind = 'issue' | 'pull_request' | 'discussion';
 
-const isValidContext = (inputs: Inputs, isPr: boolean) => {
-  if (context.eventName !== 'issue_comment') {
-    core.warning(`This action only supports the "issue_comment" event, but received "${context.eventName}".`);
-    return false;
+const validContexts = new Set<CommentKind>(['issue', 'pull_request', 'discussion']);
+
+type CommentContext = {
+  kind: CommentKind;
+  number: number;
+  commentId: number;
+  actor: string;
+};
+
+const resolveCommentContext = (): CommentContext | null => {
+  if (context.eventName === 'issue_comment') {
+    const isPr = context.payload.issue?.['pull_request'] != null;
+    return {
+      kind: isPr ? 'pull_request' : 'issue',
+      number: context.payload.issue!.number!,
+      commentId: context.payload.comment!.id,
+      actor: context.payload.comment!['user'].login,
+    };
   }
+  if (context.eventName === 'discussion_comment') {
+    const discussion = context.payload['discussion'] as { number: number } | undefined;
+    return {
+      kind: 'discussion',
+      number: discussion!.number,
+      commentId: context.payload.comment!.id,
+      actor: context.payload.comment!['user'].login,
+    };
+  }
+  return null;
+};
 
+const isValidContext = (inputs: Inputs, kind: CommentKind) => {
   const allowedContexts = str2array(inputs.allowed_contexts);
-  const invalidContexts = allowedContexts.filter((c) => !validContexts.has(c));
+  const invalidContexts = allowedContexts.filter((c) => !validContexts.has(c as CommentKind));
   if (invalidContexts.length > 0) {
-    const list = [...validContexts].map((c) => `"${c}"`).join(' and ');
+    const list = [...validContexts].map((c) => `"${c}"`).join(', ');
     core.warning(
       `The "allowed_contexts" must be a comma-separated string of ${list}, but received "${invalidContexts.join(',')}".`,
     );
     return false;
   }
 
-  if (allowedContexts.length === 1) {
-    switch (allowedContexts[0]) {
-      case 'issue': {
-        if (isPr) {
-          core.info(`💡The 'issue' context is not allowed for pull requests.`);
-          return false;
-        }
-        break;
-      }
-      case 'pull_request': {
-        if (!isPr) {
-          core.info(`💡The 'pull_request' context is not allowed for issues.`);
-          return false;
-        }
-        break;
-      }
-    }
+  if (!allowedContexts.includes(kind)) {
+    core.info(`💡The current context "${kind}" is not in allowed_contexts (${allowedContexts.join(',')}).`);
+    return false;
   }
 
   return true;
@@ -48,19 +60,27 @@ export const run = async () => {
   const inputs = getInputs();
   core.debug(`inputs: ${JSON.stringify(inputs)}`);
 
-  const isPr = context?.payload?.issue?.['pull_request'] != null;
+  const ctx = resolveCommentContext();
+  if (ctx === null) {
+    core.warning(
+      `This action only supports the "issue_comment" or "discussion_comment" event, but received "${context.eventName}".`,
+    );
+    core.setOutput('continue', 'false');
+    return 0;
+  }
 
-  if (!isValidContext(inputs, isPr)) {
+  if (!isValidContext(inputs, ctx.kind)) {
     core.setOutput('continue', 'false');
     return 0;
   }
 
-  const issueNumber = context.payload.issue!.number!;
-  core.setOutput('issue_number', issueNumber);
-  core.setOutput('number', issueNumber);
-  core.setOutput('context', isPr ? 'pull_request' : 'issue');
-  core.setOutput('comment_id', context.payload.comment!.id);
-  core.setOutput('actor', context.payload.comment!['user'].login);
+  core.setOutput('number', ctx.number);
+  core.setOutput('context', ctx.kind);
+  core.setOutput('comment_id', ctx.commentId);
+  core.setOutput('actor', ctx.actor);
+  if (ctx.kind !== 'discussion') {
+    core.setOutput('issue_number', ctx.number);
+  }
 
   const commands = str2array(inputs.command);
   const body = (context.payload.comment?.['body'] ?? '') as string;