feat: add stack to stacktraceless "exceptions"

cypress/e2e/error-tracking.cy.ts

@@ -41,6 +41,22 @@ describe('Exception capture', () => {
  cy.wait('@exception-autocapture-script')
  })
 
+ it('adds stacktrace to captured strings', () => {
+ cy.get('[data-cy-exception-string-button]').click()
+
+ // ugh
+ cy.wait(1500)
+
+ cy.phCaptures({ full: true }).then((captures) => {
+ expect(captures.map((c) => c.event)).to.deep.equal(['$pageview', '$autocapture', '$exception'])
+ expect(captures[2].event).to.be.eql('$exception')
+ expect(captures[2].properties.$exception_list[0].stacktrace.frames.length).to.be.eq(1)
+ expect(captures[2].properties.$exception_list[0].stacktrace.frames[0].function).to.be.eq(
+ 'HTMLButtonElement.onclick'
+ )
+ })
+ })
+
  it('autocaptures exceptions', () => {
  cy.get('[data-cy-button-throws-error]').click()
 

playground/cypress-full/index.html

@@ -40,6 +40,10 @@
  Send an exception
  </button>
 
+ <button data-cy-exception-string-button onclick="posthog.captureException('I am a plain old string', { extra_prop: 2 })">
+ Capture as string
+ </button>
+
  <br />
 
  <script>

playground/cypress/index.html

@@ -52,6 +52,10 @@
  Capture an exception
  </button>
 
+ <button data-cy-exception-string-button onclick="posthog.captureException('I am a plain old string', { extra_prop: 2 })">
+ Capture as string
+ </button>
+
  <script>
  !function(t,e){var o,n,p,r;e.__SV||(window.posthog=e,e._i=[],e.init=function(i,s,a){function g(t,e){var o=e.split(".");2==o.length&&(t=t[o[0]],e=o[1]),t[e]=function(){t.push([e].concat(Array.prototype.slice.call(arguments,0)))}}(p=t.createElement("script")).type="text/javascript",p.async=!0,p.src=s.api_host+"/static/array.js",(r=t.getElementsByTagName("script")[0]).parentNode.insertBefore(p,r);var u=e;for(void 0!==a?u=e[a]=[]:a="posthog",u.people=u.people||[],u.toString=function(t){var e="posthog";return"posthog"!==a&&(e+="."+a),t||(e+=" (stub)"),e},u.people.toString=function(){return u.toString(1)+".people (stub)"},o="capture identify alias people.set people.set_once set_config register register_once unregister opt_out_capturing has_opted_out_capturing opt_in_capturing reset isFeatureEnabled onFeatureFlags getSurveys getActiveMatchingSurveys captureException".split(" "),n=0;n<o.length;n++)g(u,o[n]);e._i.push([i,s,a])},e.__SV=1)}(document,window.posthog||[]);
  </script>

src/extensions/exception-autocapture/error-conversion.ts

@@ -56,7 +56,7 @@ export interface ErrorConversions {
 const ERROR_TYPES_PATTERN =
  /^(?:[Uu]ncaught (?:exception: )?)?(?:((?:Eval|Internal|Range|Reference|Syntax|Type|URI|)Error): )?(.*)$/i
 
-export function parseStackFrames(ex: Error & { framesToPop?: number; stacktrace?: string }): StackFrame[] {
+export function parseStackFrames(ex: Error & { stacktrace?: string }, framesToPop: number = 0): StackFrame[] {
  // Access and store the stacktrace property before doing ANYTHING
  // else to it because Opera is not very good at providing it
  // reliably in other circumstances.
@@ -65,7 +65,9 @@ export function parseStackFrames(ex: Error & { framesToPop?: number; stacktrace?
  const skipLines = getSkipFirstStackStringLines(ex)
 
  try {
- return defaultStackParser(stacktrace, skipLines)
+ const frames = defaultStackParser(stacktrace, skipLines)
+ // frames are reversed so we remove the from the back of the array
+ return frames.slice(0, frames.length - framesToPop)
  } catch {
  // no-empty
  }
@@ -146,17 +148,26 @@ function errorPropertiesFromString(candidate: string, metadata?: ErrorMetadata):
  ? candidate
  : metadata?.defaultExceptionMessage
 
+ const exception: Exception = {
+ type: exceptionType,
+ value: exceptionMessage,
+ mechanism: {
+ handled,
+ synthetic,
+ },
+ }
+
+ if (metadata?.syntheticException) {
+ // Kludge: strip the last frame from a synthetically created error
+ // so that it does not appear in a users stack trace
+ const frames = parseStackFrames(metadata.syntheticException, 1)
+ if (frames.length) {
+ exception.stacktrace = { frames }
+ }
+ }
+
  return {
- $exception_list: [
- {
- type: exceptionType,
- value: exceptionMessage,
- mechanism: {
- handled,
- synthetic,
- },
- },
- ],
+ $exception_list: [exception],
  $exception_level: 'error',
  }
 }
@@ -206,17 +217,26 @@ function errorPropertiesFromObject(candidate: Record<string, unknown>, metadata?
  ? metadata.overrideExceptionMessage
  : `Non-Error ${'exception'} captured with keys: ${extractExceptionKeysForMessage(candidate)}`
 
+ const exception: Exception = {
+ type: exceptionType,
+ value: exceptionMessage,
+ mechanism: {
+ handled,
+ synthetic,
+ },
+ }
+
+ if (metadata?.syntheticException) {
+ // Kludge: strip the last frame from a synthetically created error
+ // so that it does not appear in a users stack trace
+ const frames = parseStackFrames(metadata?.syntheticException, 1)
+ if (frames.length) {
+ exception.stacktrace = { frames }
+ }
+ }
+
  return {
- $exception_list: [
- {
- type: exceptionType,
- value: exceptionMessage,
- mechanism: {
- handled,
- synthetic,
- },
- },
- ],
+ $exception_list: [exception],
  $exception_level: isSeverityLevel(candidate.level) ? candidate.level : 'error',
  }
 }
@@ -259,7 +279,7 @@ export function errorToProperties(
  } else if (isPlainObject(candidate) || isEvent(candidate)) {
  // group these by using the keys available on the object
  const objectException = candidate as Record<string, unknown>
- return errorPropertiesFromObject(objectException)
+ return errorPropertiesFromObject(objectException, metadata)
  } else if (isUndefined(error) && isString(event)) {
  let name = 'Error'
  let message = event

src/extensions/exception-autocapture/stack-trace.ts

@@ -51,7 +51,6 @@ export interface StackFrame {
 }
 
 const WEBPACK_ERROR_REGEXP = /\(error: (.*)\)/
-const STRIP_FRAME_REGEXP = /captureException/
 const STACKTRACE_FRAME_LIMIT = 50
 
 const UNKNOWN_FUNCTION = '?'
@@ -210,14 +209,6 @@ export function reverseAndStripFrames(stack: ReadonlyArray<StackFrame>): StackFr
 
  localStack.reverse()
 
- if (STRIP_FRAME_REGEXP.test(getLastStackFrame(localStack).function || '')) {
- localStack.pop()
-
- if (STRIP_FRAME_REGEXP.test(getLastStackFrame(localStack).function || '')) {
- localStack.pop()
- }
- }
-
  return localStack.slice(0, STACKTRACE_FRAME_LIMIT).map((frame) => ({
  ...frame,
  filename: frame.filename || getLastStackFrame(localStack).filename,

src/extensions/exception-autocapture/type-checking.ts

@@ -27,6 +27,7 @@ export function isError(candidate: unknown): candidate is Error {
  case '[object Error]':
  case '[object Exception]':
  case '[object DOMException]':
+ case '[object DOMError]':
  return true
  default:
  return isInstanceOf(candidate, Error)

src/posthog-core.ts

@@ -1826,14 +1826,15 @@ export class PostHog {
 
  /** Capture a caught exception manually */
  captureException(error: Error, additionalProperties?: Properties): void {
+ const syntheticException = new Error('PostHog syntheticException')
  const properties: Properties = isFunction(assignableWindow.__PosthogExtensions__?.parseErrorAsProperties)
- ? assignableWindow.__PosthogExtensions__.parseErrorAsProperties([
- error.message,
- undefined,
- undefined,
- undefined,
- error,
- ])
+ ? assignableWindow.__PosthogExtensions__.parseErrorAsProperties(
+ [error.message, undefined, undefined, undefined, error],
+ // create synthetic error to get stack in cases where user input does not contain one
+ // creating the exceptionas soon into our code as possible means we should only have to
+ // remove a single frame (this 'captureException' method) from the resultant stack
+ { syntheticException }
+ )
  : {
  $exception_level: 'error',
  $exception_list: [

src/types.ts

@@ -573,6 +573,7 @@ export type ErrorEventArgs = [
 export type ErrorMetadata = {
  handled?: boolean
  synthetic?: boolean
+ syntheticException?: Error
  overrideExceptionType?: string
  overrideExceptionMessage?: string
  defaultExceptionType?: string