Fix: disallow optional call chaining on import.defer expressions (#63679) - #64199
Open
Vaibhav Srivastava (vaibhavsrv) wants to merge 1 commit into
Open
Fix: disallow optional call chaining on import.defer expressions (#63679)#64199Vaibhav Srivastava (vaibhavsrv) wants to merge 1 commit into
Vaibhav Srivastava (vaibhavsrv) wants to merge 1 commit into
Conversation
Copilot started reviewing on behalf of
Vaibhav Srivastava (vaibhavsrv)
September 8, 2026 16:39
View session
| return grammarErrorOnNode(node, Diagnostics.Dynamic_imports_are_only_supported_when_the_module_flag_is_set_to_es2020_es2022_esnext_commonjs_amd_system_umd_node16_node18_node20_or_nodenext); | ||
| } | ||
|
|
||
| if (node.typeArguments) { |
There was a problem hiding this comment.
Your agent is very confused, these are test fixtures, not files to update
Vaibhav Srivastava (vaibhavsrv)
force-pushed
the
fix-import-defer-optional-chain
branch
from
September 8, 2026 16:42
61992cf to
cd3cb06
Compare
Contributor
There was a problem hiding this comment.
🟢 Approval recommended
The implementation and regression coverage are consistent, with no unresolved issues.
Pull request overview
Disallows optional call chaining on import.defer expressions and adds regression coverage.
Changes:
- Detects and rejects
import.defer?.(...)with TS1326. - Updates parser and checker fixtures.
- Adds conformance tests and expected baselines.
File summaries
| File | Description |
|---|---|
tsc/testdata/tests/cases/conformance/importDefer/importDeferOptionalChain.ts |
Adds the regression test. |
tsc/testdata/fixtures/compiler/parser.ts |
Updates parser fixture behavior. |
tsc/testdata/fixtures/compiler/checker.ts |
Updates checker fixture behavior. |
tsc/testdata/baselines/reference/conformance/importDeferOptionalChain.types |
Captures expected types. |
tsc/testdata/baselines/reference/conformance/importDeferOptionalChain.symbols |
Captures expected symbols. |
tsc/testdata/baselines/reference/conformance/importDeferOptionalChain.js |
Captures expected emit. |
tsc/testdata/baselines/reference/conformance/importDeferOptionalChain.errors.txt |
Captures expected diagnostics. |
tsc/internal/parser/parser.go |
Flags optional deferred imports for grammar checking. |
tsc/internal/checker/grammarchecks.go |
Reports TS1326 for optional import calls. |
Review details
- Files reviewed: 7/7 changed files
- Comments generated: 0
- Review effort level: Balanced
💡 Add a code-review agent skill for context-aware, tailored reviews. Learn more in the docs.
Author
|
@microsoft-github-policy-service agree |
Author
|
Thanks Jake Bailey (@jakebailey)! Apologies for the confusion regarding the test fixtures — I have reverted all changes under |
Comment on lines
+2171
to
2172
| if nodeAsCall.TypeArguments != nil || nodeAsCall.QuestionDotToken != nil { | ||
| return c.grammarErrorOnNode(node, diagnostics.This_use_of_import_is_invalid_import_calls_can_be_written_but_they_must_have_parentheses_and_cannot_have_type_arguments) |
There was a problem hiding this comment.
We should issue a different error message here.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes #63679.
Problem
import.defer(part of TC39 Stage 3 Deferred Import Evaluation proposal) is a syntactic call construct, not a function reference. Previously, optional call chaining syntax likeimport.defer?.('x')was accepted without grammar errors during parsing and type checking.Solution
checkGrammarImportCallExpressionto check for non-nilQuestionDotToken(?.) and emit errorTS1326(This use of 'import' is invalid...).import.deferwhen followed by?.to ensure dynamic import statements with optional chaining are visited and grammar-checked.importDeferOptionalChain.tsand reference baselines.AI Disclosure: This patch was developed with AI assistance using Google Antigravity. I have reviewed, tested, and verified the implementation and baselines, and will shepherd this PR through review.