feat: Remove ANSI control chars from GitHub step Summary and PR comment

CHANGELOG.md

@@ -2,9 +2,8 @@
 
 ## HEAD (Unreleased)
 
-**(none)**
-
----
+- feat: Strip ansi control characters from GitHub step Summary and PR comment
+  ([#1312](https://github.com/pulumi/actions/pull/1312))
 
 ## 6.4.0 (2025-07-16)
 

package.json

@@ -49,7 +49,6 @@
     "@actions/tool-cache": "^2.0.1",
     "@pulumi/pulumi": "3.165.0",
     "actions-parsers": "^1.0.2",
-    "ansi-to-html": "^0.7.2",
     "dedent": "^0.7.0",
     "envalid": "^7.3.1",
     "got": "^11.8.6",

src/libs/__tests__/pr.test.ts

@@ -50,12 +50,12 @@ describe('pr.ts', () => {
 
     await handlePullRequestMessage(defaultOptions, projectName, 'test');
     expect(createComment).toHaveBeenCalledWith({
-      body: '#### :tropical_drink: `preview` on myFirstProject/staging\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\ntest\n</pre>\n\n</details>',
+      body: `#### :tropical_drink: \`preview\` on ${projectName}/${defaultOptions.stackName}\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\ntest\n</pre>\n\n</details>`,
       issue_number: 123,
     });
   });
 
-  it('should convert ansi control character to html and add to pull request message', async () => {
+  it('should convert ansi control character to plain text and add to pull request message', async () => {
     // @ts-ignore
     gh.context = {
       payload: {
@@ -69,7 +69,7 @@ describe('pr.ts', () => {
 
     await handlePullRequestMessage(defaultOptions, projectName, '\x1b[30mblack\x1b[37mwhite');
     expect(createComment).toHaveBeenCalledWith({
-      body: '#### :tropical_drink: `preview` on myFirstProject/staging\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\n<span style="color:#000">black<span style="color:#AAA">white</span></span>\n</pre>\n\n</details>',
+      body: `#### :tropical_drink: \`preview\` on ${projectName}/${defaultOptions.stackName}\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\nblackwhite\n</pre>\n\n</details>`,
       issue_number: 123,
     });
   });
@@ -93,7 +93,7 @@ describe('pr.ts', () => {
 
     await handlePullRequestMessage(options, projectName, 'test');
     expect(createComment).toHaveBeenCalledWith({
-      body: '#### :tropical_drink: `preview` on myFirstProject/staging\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\ntest\n</pre>\n\n</details>',
+      body: `#### :tropical_drink: \`preview\` on ${projectName}/${options.stackName}\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\ntest\n</pre>\n\n</details>`,
       issue_number: 87,
     });
   });
@@ -120,7 +120,7 @@ describe('pr.ts', () => {
 
     await handlePullRequestMessage(options, projectName, 'test');
     expect(createComment).toHaveBeenCalledWith({
-      body: '#### :tropical_drink: `preview` on myFirstProject/staging\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\ntest\n</pre>\n\n</details>',
+      body: `#### :tropical_drink: \`preview\` on ${projectName}/${options.stackName}\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\ntest\n</pre>\n\n</details>`,
       issue_number: 87,
     });
   });
@@ -158,15 +158,14 @@ describe('pr.ts', () => {
         },
       },
     };
-    const alwaysIncludeSummaryOptions = {
-      command: 'preview',
-      stackName: 'staging',
+
+    const options: Config = {
+      ...defaultOptions,
       alwaysIncludeSummary: true,
-      options: {},
-    } as Config;
+    };
 
     await handlePullRequestMessage(
-      alwaysIncludeSummaryOptions,
+      options,
       projectName,
       'a'.repeat(65_000) + '\n' + 'this is at the end and should be in the output',
     );
@@ -182,17 +181,16 @@ describe('pr.ts', () => {
     // @ts-ignore
     gh.context = { repo: {} };
 
-    const options = {
-      command: 'preview',
-      stackName: 'staging',
+    const options: Config = {
+      ...defaultOptions,
       commentOnPrNumber: 123,
       editCommentOnPr: true,
-    } as Config;
+    };
 
     await handlePullRequestMessage(options, projectName, 'test');
     expect(updateComment).toHaveBeenCalledWith({
       comment_id: 2,
-      body: '#### :tropical_drink: `preview` on myFirstProject/staging\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\ntest\n</pre>\n\n</details>',
+      body: `#### :tropical_drink: \`preview\` on ${projectName}/${options.stackName}\n\n<details>\n<summary>Pulumi report</summary>\n\n\n<pre>\ntest\n</pre>\n\n</details>`,
     });
   });
 

src/libs/__tests__/summary.test.ts

@@ -0,0 +1,112 @@
+import * as fs from 'fs'
+import path from 'path'
+import * as core from '@actions/core';
+import { SUMMARY_ENV_VAR } from '@actions/core/lib/summary'
+import { Config } from '../../config';
+import { handleSummaryMessage } from '../summary';
+
+const testDirectoryPath = path.join(__dirname, 'test')
+const testFilePath = path.join(testDirectoryPath, 'test-summary.md')
+
+async function getSummary(): Promise<string> {
+  const file = await fs.promises.readFile(testFilePath, {encoding: 'utf8'});
+  return file.replace(/\r\n/g, '\n');
+}
+
+const projectName = 'myFirstProject';
+const defaultOptions = {
+  command: 'preview',
+  stackName: 'staging',
+  options: {},
+} as Config;
+
+describe('summary.ts', () => {
+  beforeEach(async () => {
+    process.env[SUMMARY_ENV_VAR] = testFilePath;
+    await fs.promises.mkdir(testDirectoryPath, {recursive: true});
+    await fs.promises.writeFile(testFilePath, '', {encoding: 'utf8'});
+    core.summary.emptyBuffer();
+  })
+
+  afterAll(async () => {
+    await fs.promises.unlink(testFilePath);
+  })
+
+  it('throws if summary env var is undefined', async () => {
+    process.env[SUMMARY_ENV_VAR] = undefined;
+    const write = core.summary.addRaw('123').write();
+    await expect(write).rejects.toThrow();
+  })
+
+  it('throws if summary file does not exist', async () => {
+    await fs.promises.unlink(testFilePath);
+    const write = core.summary.addRaw('123').write();
+    await expect(write).rejects.toThrow();
+  })
+
+  it('should add only heading with empty code block to summary', async () => {
+    const message = '';
+    const expected = `<h1>Pulumi ${projectName}/${defaultOptions.stackName} results</h1>\n<pre lang="diff"><code></pre>\n`;
+
+    await handleSummaryMessage(defaultOptions, projectName, message);
+    const summary = await getSummary()
+
+    expect(summary).toBe(expected);
+  })
+
+  it('should convert ansi control character to plain text and add to summary', async () => {
+    const message = '\x1b[30mblack\x1b[37mwhite';
+    const expected = `<h1>Pulumi ${projectName}/${defaultOptions.stackName} results</h1>\n<pre lang="diff"><code>blackwhite</code></pre>\n`;
+
+    await handleSummaryMessage(defaultOptions, projectName, message);
+    const summary = await getSummary()
+
+    expect(summary).toBe(expected);
+  })
+
+  it('should trim the output when the output is larger than 1 MiB', async () => {
+    const message = 'this is at the begining and should not be in the output' + 'a'.repeat(1_048_576) + 'this is at the end and should be in the output';
+
+    await handleSummaryMessage(defaultOptions, projectName, message);
+    const summary = await getSummary()
+
+    expect(Buffer.byteLength(summary, 'utf8')).toBeLessThan(1_048_576);
+    expect(summary).toContain('this is at the begining and should not be in the output')
+    expect(summary).toContain('The output was too long and trimmed.');
+    expect(summary).not.toContain('this is at the end and should be in the output');
+    expect(summary).not.toContain('The output was too long and trimmed from the front.');
+  })
+
+  it('should trim the output from front when the output is larger than 1 MiB and config is set', async () => {
+    const message = 'this is at the begining and should not be in the output' + 'a'.repeat(1_048_576) + 'this is at the end and should be in the output';
+
+    const options: Config = {
+      ...defaultOptions,
+      alwaysIncludeSummary: true,
+    };
+
+    await handleSummaryMessage(options, projectName, message);
+    const summary = await getSummary()
+
+    expect(Buffer.byteLength(summary, 'utf8')).toBeLessThan(1_048_576);
+    expect(summary).toContain('this is at the end and should be in the output');
+    expect(summary).toContain('The output was too long and trimmed from the front.');
+    expect(summary).not.toContain('this is at the begining and should not be in the output')
+    expect(summary).not.toContain('The output was too long and trimmed.');
+  })
+
+  it('should replace first leading space with non-breaking space character to preserve the formatting', async () => {
+    const message = 
+`begin
+      some leading spaces in this line
+`;
+
+    const expected = `<h1>Pulumi ${projectName}/${defaultOptions.stackName} results</h1>\n<pre lang="diff"><code>begin\n&nbsp;     some leading spaces in this line\n</code></pre>\n`;
+
+    await handleSummaryMessage(defaultOptions, projectName, message);
+    const summary = await getSummary()
+
+    expect(summary).toBe(expected);
+  })
+
+})

src/libs/__tests__/utils.test.ts

@@ -1,4 +1,4 @@
-import { parseSemicolorToArray } from '../utils';
+import { parseSemicolorToArray, stripAnsiControlCodes } from '../utils';
 
 describe('utils.ts', () => {
   it('should parse semicolon to array', () => {
@@ -9,3 +9,12 @@ describe('utils.ts', () => {
     expect(inputArray[1]).toBe('world');
   });
 });
+
+describe('utils.ts', () => {
+  it('should parse semicolon to array', () => {
+
+    const output = stripAnsiControlCodes('\x1b[30mblack\x1b[37mwhite');
+
+    expect(output).toBe('blackwhite');
+  });
+});

src/libs/pr.ts

@@ -1,47 +1,41 @@
 import * as core from '@actions/core';
 import { context, getOctokit } from '@actions/github';
-import AnsiToHtml from 'ansi-to-html';
 import dedent from 'dedent';
 import invariant from 'ts-invariant';
 import { Config } from '../config';
+import { stripAnsiControlCodes } from './utils';
 
-function ansiToHtml(
+function trimOutputByCharacters(
   message: string,
   maxLength: number,
   alwaysIncludeSummary: boolean,
 ): [string, boolean] {
   /**
-   *  Converts an ansi string to html by for example removing color escape characters.
-   *  message: ansi string to convert
-   *  maxLength: Maximum number of characters of final message incl. HTML tags
+   *  Trim message to maxLength
+   *  message: string to trim
+   *  maxLength: Maximum number of characters of final message
    *  alwaysIncludeSummary: if true, trim message from front (if trimming is needed), otherwise from end
    *
-   *  return message as html and information if message was trimmed because of length
+   *  return message and information if message was trimmed
    */
-  const convert = new AnsiToHtml();
   let trimmed = false;
 
-  let htmlBody: string = convert.toHtml(message);
+  // Check if message exceeds max characters
+  if (message.length > maxLength) {
 
-  // Check if htmlBody exceeds max characters
-  if (htmlBody.length > maxLength) {
-
-    // trim input message by number of exceeded characters from front or back as configured
-    const dif: number = htmlBody.length - maxLength;
+    // Trim input message by number of exceeded characters from front or back as configured
+    const dif: number = message.length - maxLength;
 
     if (alwaysIncludeSummary) {
-      message = message.substring(dif, htmlBody.length);
+      message = message.substring(dif, message.length);
     } else {
       message = message.substring(0, message.length - dif);
     }
 
     trimmed = true;
-
-    // convert trimmed message to html
-    htmlBody = convert.toHtml(message);
   }
 
-  return [htmlBody, trimmed];
+  return [message, trimmed];
 }
 
 function extractViewLiveLink(output: string) {
@@ -72,14 +66,17 @@ export async function handlePullRequestMessage(
     alwaysIncludeSummary,
   } = config;
 
-  // GitHub limits comment characters to 65535, use lower max to keep buffer for variable values
+  // Remove ANSI symbols from output because they are not supported in GitHub PR message
+  output = stripAnsiControlCodes(output);
+
+  // GitHub limits PR comment characters to 65_535, use lower max to keep buffer for variable values
   const MAX_CHARACTER_COMMENT = 64_000;
 
   const heading = `#### :tropical_drink: \`${command}\` on ${projectName}/${stackName}`;
 
   const summary = '<summary>Pulumi report</summary>';
 
-  const [htmlBody, trimmed]: [string, boolean] = ansiToHtml(output, MAX_CHARACTER_COMMENT, alwaysIncludeSummary);
+  const [message, trimmed]: [string, boolean] = trimOutputByCharacters(output, MAX_CHARACTER_COMMENT, alwaysIncludeSummary);
 
   const viewLiveLink = extractViewLiveLink(output);
 
@@ -94,7 +91,7 @@ export async function handlePullRequestMessage(
       : ''
     }
     <pre>
-    ${htmlBody}
+    ${message}
     </pre>
     ${trimmed && !alwaysIncludeSummary
       ? ':warning: **Warn**: The output was too long and trimmed.'