handle error assertions more gracefully

Problem:

Sometimes we try and assert a specific error, but up the call stack that
error may get wrapped in a `ToolkitError` and now exists in the `cause`.

Then when we test we need to know where exactly in the `cause` chain our expected
error is. This is annoying.

Solution:

Create a function which recursively goes through the cause chain searching for
the expected error.

Signed-off-by: nkomonen-amazon <[email protected]>

Author: nkomonen-amazon

packages/core/src/test/credentials/auth.test.ts

@@ -9,7 +9,7 @@ import fs from '../../shared/fs/fs'
 import { ToolkitError, isUserCancelledError } from '../../shared/errors'
 import { assertTreeItem } from '../shared/treeview/testUtil'
 import { getTestWindow } from '../shared/vscode/window'
-import { assertTelemetry, captureEventOnce } from '../testUtil'
+import { assertError as assertHasError, assertTelemetry, captureEventOnce } from '../testUtil'
 import { createBuilderIdProfile, createSsoProfile, createTestAuth } from './testUtil'
 import { toCollection } from '../../shared/utilities/asyncCollection'
 import globals from '../../shared/extensionGlobals'
@@ -316,7 +316,7 @@ describe('Auth', function () {
             auth.getTestTokenProvider(conn)?.getToken.rejects(err1)
             const err2 = await runExpiredConnectionFlow(conn, /no/i).catch((e) => e)
             assert.ok(err2 instanceof ToolkitError)
-            assert.strictEqual(err2.cause, err1)
+            assertHasError(err2.cause, err1)
         })
 
         it('bubbles up networking issues instead of invalidating the connection', async function () {
@@ -325,7 +325,7 @@ describe('Auth', function () {
             auth.getTestTokenProvider(conn)?.getToken.rejects(expected)
             const actual = await conn.getToken().catch((e) => e)
             assert.ok(actual instanceof ToolkitError)
-            assert.strictEqual(actual.cause, expected)
+            assertHasError(actual, expected)
             assert.strictEqual(auth.getConnectionState(conn), 'valid')
         })
 
@@ -339,7 +339,7 @@ describe('Auth', function () {
             auth.getTestTokenProvider(conn)?.getToken.rejects(networkError)
             const actual = await auth.refreshConnectionState(conn).catch((e) => e)
             assert.ok(actual instanceof ToolkitError)
-            assert.deepStrictEqual(actual, expectedError)
+            assertHasError(actual, expectedError)
             assert.strictEqual(auth.getConnectionState(conn), 'valid')
         })
 

packages/core/src/test/testUtil.ts

@@ -19,6 +19,7 @@ import { mkdirSync, existsSync } from 'fs' // eslint-disable-line no-restricted-
 import { randomBytes } from 'crypto'
 import request from '../shared/request'
 import { stub } from 'sinon'
+import { ToolkitError } from '../shared'
 
 const testTempDirs: string[] = []
 
@@ -623,3 +624,19 @@ export function tryRegister(command: DeclaredCommand<() => Promise<any>>) {
 export function getFetchStubWithResponse(response: Partial<Response>) {
     return stub(request, 'fetch').returns({ response: new Promise((res, _) => res(response)) } as any)
 }
+
+/**
+ * Asserts that the errors match, or at least exists somewhere in the `cause` chain
+ */
+export function assertError(actual: unknown, expected: unknown) {
+    try {
+        return assert.deepStrictEqual(actual, expected)
+    } catch (e) {
+        if (!(actual instanceof ToolkitError)) {
+            throw e
+        }
+    }
+    assert(actual instanceof ToolkitError) // make linter happy
+    // recursively search causal chaing for matching error
+    assertError(actual.cause, expected)
+}