fix(errors): preserve stack tail in report url

src/dialogs/errors.js

@@ -4,24 +4,78 @@ const os = require('os')
 const i18n = require('i18next')
 const dialog = require('./dialog')
 
+// GitHub responds HTTP 414 (URI too long) on the issue-creation form around
+// 8200 chars; 8000 leaves headroom for request line and headers.
+const MAX_URL_LENGTH = 8000
+
+// When forced to truncate, keep more from the tail than the head: daemon
+// migration logs wrapped in `new Error(logs)` (see daemon/migration-prompt.js)
+// put the real cause on the last lines (see issue #3147).
+const TRUNCATION_STEPS = [
+  [5, 30],
+  [3, 25],
+  [2, 20],
+  [1, 15],
+  [1, 10],
+  [0, 8],
+  [0, 5],
+  [0, 3]
+]
+
 const issueTitle = (e) => {
-  const es = e.stack ? e.stack.toString() : 'unknown error, no stacktrace'
-  const firstLine = es.substr(0, Math.min(es.indexOf('\n'), 72))
+  const stack = e && e.stack ? e.stack.toString() : 'unknown error, no stacktrace'
+  const newlineIdx = stack.indexOf('\n')
+  const lineEnd = newlineIdx === -1 ? stack.length : newlineIdx
+  const firstLine = stack.slice(0, Math.min(lineEnd, 72))
   return `[gui error report] ${firstLine}`
 }
 
-const issueTemplate = (e) => `<!-- 👉️ Please describe HERE what you were doing when this error happened. -->
+const issueTemplate = (stack) => `<!-- 👉️ Please describe HERE what you were doing when this error happened. -->
 
 - **Desktop**: ${app.getVersion()}
 - **OS**: ${os.platform()} ${os.release()} ${os.arch()}
 - **Electron**: ${process.versions.electron}
 - **Chrome**: ${process.versions.chrome}
 
 \`\`\`
-${e.stack}
+${stack}
 \`\`\`
 `
 
+function truncateStack (stack, headLines, tailLines) {
+  const lines = stack.split('\n')
+  if (lines.length <= headLines + tailLines) return stack
+  const head = lines.slice(0, headLines)
+  const tail = lines.slice(lines.length - tailLines)
+  const omitted = lines.length - headLines - tailLines
+  return [
+    ...head,
+    `... ${omitted} lines omitted ...`,
+    ...tail
+  ].join('\n')
+}
+
+function buildBugReportUrl (title, body) {
+  return `https://github.com/ipfs/ipfs-desktop/issues/new?labels=kind%2Fbug%2C+need%2Ftriage&template=bug_report.md&title=${encodeURIComponent(title)}&body=${encodeURIComponent(body)}`
+}
+
+// Returns an issue-creation URL within MAX_URL_LENGTH. Tries the full stack
+// first, then shrinks via head+tail truncation, always preserving the tail.
+function generateBugReportUrl (e) {
+  const title = issueTitle(e)
+  const stack = e && e.stack ? e.stack.toString() : 'unknown error, no stacktrace'
+
+  let url = buildBugReportUrl(title, issueTemplate(stack))
+  if (url.length <= MAX_URL_LENGTH) return url
+
+  for (const [h, t] of TRUNCATION_STEPS) {
+    url = buildBugReportUrl(title, issueTemplate(truncateStack(stack, h, t)))
+    if (url.length <= MAX_URL_LENGTH) return url
+  }
+
+  return url.slice(0, MAX_URL_LENGTH)
+}
+
 let hasErrored = false
 
 function generateErrorIssueUrl (e) {
@@ -70,7 +124,7 @@ function generateErrorIssueUrl (e) {
     }
   }
   // Something else, prefill new issue form with error details
-  return `https://github.com/ipfs/ipfs-desktop/issues/new?labels=kind%2Fbug%2C+need%2Ftriage&template=bug_report.md&title=${encodeURI(issueTitle(e))}&body=${encodeURI(issueTemplate(e))}`.substring(0, 1999)
+  return generateBugReportUrl(e)
 }
 
 /**

test/unit/errors.spec.js

@@ -0,0 +1,113 @@
+const proxyquire = require('proxyquire').noCallThru()
+const { test, expect } = require('@playwright/test')
+
+const electronMock = {
+  app: {
+    getVersion: () => '0.49.0',
+    relaunch: () => {},
+    exit: () => {},
+    getPath: () => '/tmp'
+  },
+  shell: {
+    openExternal: () => {},
+    openPath: () => {}
+  }
+}
+
+const i18nMock = { t: (key) => key }
+
+const { generateErrorIssueUrl } = proxyquire('../../src/dialogs/errors', {
+  electron: electronMock,
+  i18next: i18nMock,
+  './dialog': () => 0
+})
+
+const MAX_URL_LENGTH = 8000
+
+function decodeBody (url) {
+  const match = url.match(/[?&]body=([^&]*)/)
+  return match ? decodeURIComponent(match[1]) : ''
+}
+
+function decodeTitle (url) {
+  const match = url.match(/[?&]title=([^&]*)/)
+  return match ? decodeURIComponent(match[1]) : ''
+}
+
+test.describe('generateErrorIssueUrl', () => {
+  test('returns FAQ link for known error patterns instead of a new-issue URL', () => {
+    const e = { stack: 'Error: repo.lock is held by another process' }
+    const url = generateErrorIssueUrl(e)
+    expect(url).toBe('https://github.com/ipfs/ipfs-desktop?tab=readme-ov-file#i-got-a-repolock-error-how-do-i-resolve-this')
+  })
+
+  test('produces a new-issue URL for unknown errors', () => {
+    const e = { stack: 'Error: something we have not seen before\n    at fn (file.js:1:1)' }
+    const url = generateErrorIssueUrl(e)
+    expect(url).toContain('https://github.com/ipfs/ipfs-desktop/issues/new')
+    expect(url).toContain('title=')
+    expect(url).toContain('body=')
+  })
+
+  test('keeps URL within the 8000-char safety limit even for very long stacks', () => {
+    const longStack = 'Error: kaboom\n' + Array(2000).fill('    at someFunction (/very/long/path/to/file.js:123:45)').join('\n')
+    const url = generateErrorIssueUrl({ stack: longStack })
+    expect(url.length).toBeLessThanOrEqual(MAX_URL_LENGTH)
+  })
+
+  test('preserves the last lines of the stack when truncating (where daemon errors live)', () => {
+    const lastLine = 'Error: fs-repo-12-to-13/verify-repo-version: failed to verify repo'
+    const longStack = [
+      'Error: Initializing daemon...',
+      ...Array(2000).fill('Fetching with HTTP: https://trustless-gateway.link/ipfs/Qm...'),
+      lastLine
+    ].join('\n')
+    const url = generateErrorIssueUrl({ stack: longStack })
+    expect(url.length).toBeLessThanOrEqual(MAX_URL_LENGTH)
+    expect(decodeBody(url)).toContain(lastLine)
+  })
+
+  test('includes a marker indicating omitted lines when truncated', () => {
+    const longStack = 'Error: kaboom\n' + Array(2000).fill('    at fn (file.js:1:1)').join('\n')
+    const url = generateErrorIssueUrl({ stack: longStack })
+    expect(decodeBody(url)).toMatch(/\.\.\. \d+ lines omitted \.\.\./)
+  })
+
+  test('does not truncate stacks small enough to fit', () => {
+    const stack = 'Error: small\n    at fn (file.js:1:1)\n    at fn2 (file.js:2:2)'
+    const url = generateErrorIssueUrl({ stack })
+    expect(decodeBody(url)).toContain(stack)
+    expect(decodeBody(url)).not.toMatch(/lines omitted/)
+  })
+
+  test('issueTitle handles stacks without a newline', () => {
+    const url = generateErrorIssueUrl({ stack: 'short error message no newlines' })
+    expect(decodeTitle(url)).toBe('[gui error report] short error message no newlines')
+  })
+
+  test('issueTitle truncates very long single-line errors to 72 chars', () => {
+    const longLine = 'Error: ' + 'a'.repeat(200)
+    const url = generateErrorIssueUrl({ stack: longLine })
+    const title = decodeTitle(url)
+    expect(title.length).toBe('[gui error report] '.length + 72)
+  })
+
+  test('issueTitle handles missing stack gracefully', () => {
+    const url = generateErrorIssueUrl({})
+    expect(decodeTitle(url)).toBe('[gui error report] unknown error, no stacktrace')
+  })
+
+  test('properly encodes ampersand and other reserved chars in stack', () => {
+    const e = { stack: 'Error: foo & bar = baz # qux\n    at fn (file.js:1:1)' }
+    const url = generateErrorIssueUrl(e)
+    // Query string must have exactly four params: labels, template, title, body.
+    // An unencoded & in the body would inflate this count.
+    const queryStart = url.indexOf('?')
+    const params = url.slice(queryStart + 1).split('&')
+    expect(params.length).toBe(4)
+    // The literal & should be percent-encoded inside body.
+    expect(url).toContain('%26')
+    // Decoded body should still contain the original chars.
+    expect(decodeBody(url)).toContain('foo & bar = baz # qux')
+  })
+})