feat: completion snippets by a-tarasyuk · Pull Request #3949 · microsoft/typescript-go

a-tarasyuk · 2026-05-18T13:27:30Z

Copilot

Pull request overview

Adds snippet-aware completion behavior to the Go-based TypeScript language service port (tsgo), including new user preference flags, richer completion items (snippets/label details/additional edits), and updated fourslash conversion + generated tests to validate the new completion shapes.

Changes:

Implement snippet-based completion entries for class member stubs, object-literal method stubs, and import-statement completions (including label details and additional text edits where applicable).
Add new UserPreferences flags controlling snippet text and label-details behavior, and thread them through completion generation.
Update fourslash harness + conversion scripts and regenerate/add tests to cover the new completion item shapes and preferences.

Reviewed changes

Copilot reviewed 60 out of 84 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
internal/ls/utilities.go	Fix single-quote `quote()` output to include surrounding quotes (used by snippet generation).
internal/ls/string_completions.go	Update completion item construction for new `additionalTextEdits` parameter.
internal/ls/lsutil/userpreferences.go	Add snippet/label-details completion preference flags and clean up struct tags/comments.
internal/ls/completions.go	Main implementation of snippet completions (class member stubs, object-literal method stubs, import statement completions), plus new sort text helpers and completion item plumbing.
internal/ls/codeactions_missingmemberfixer.go	Extend missing-member fixer to support abstract context and safer auto-import symbol handling.
internal/ls/codeactions_fixclassincorrectlyimplementsinterface.go	Update call site for new missing-member fixer signature.
internal/ls/change/trackerimpl.go	Export `GetFormatCodeSettingsForWriting` for reuse by snippet formatting paths.
internal/ls/autoimport/view.go	Add a nil-safe/availability-checked export lookup helper for auto-import views.
internal/ls/autoimport/import_adder.go	Make auto-import export lookup resilient when the view index isn’t available by falling back to the direct export.
internal/ls/autoimport/extract.go	Exclude pattern ambient modules from ambient module export extraction.
internal/fourslash/tests/completionClassMembersAfterConstAssertionInitializer_test.go	Update expected completion to include inserted text for a class member.
internal/fourslash/fourslash.go	Improve preference override handling during tests; adjust strictness/normalization in completion comparisons; set CRLF for Strada server tests.
internal/fourslash/_scripts/unparsedTests.txt	Update parsing error messages to reflect improved conversion handling for sources/sortText.
internal/fourslash/_scripts/failingTests.txt	Remove several tests from failing list as conversions/expectations are now supported.
internal/fourslash/_scripts/convertFourslash.mts	Extend converter to handle format options, completion sources, labelDetails, preferences, and object-literal sortText helpers.
internal/checker/nodecopy.go	Preserve qualifier symbol links when copying `import()` type nodes.
internal/fourslash/tests/gen/jsxTagNameCompletionWithExistingJsxInitializer_test.go	Regenerated: pass snippet-enabled user preferences for JSX attribute snippet behavior.
internal/fourslash/tests/gen/jsxTagNameCompletionUnderElementUnclosed_test.go	Regenerated: pass snippet-enabled user preferences for JSX attribute snippet behavior.
internal/fourslash/tests/gen/jsxTagNameCompletionUnderElementClosed_test.go	Regenerated: pass snippet-enabled user preferences for JSX attribute snippet behavior.
internal/fourslash/tests/gen/jsxTagNameCompletionUnclosed_test.go	Regenerated: pass snippet-enabled user preferences for JSX attribute snippet behavior.
internal/fourslash/tests/gen/jsxTagNameCompletionClosed_test.go	Regenerated: pass snippet-enabled user preferences for JSX attribute snippet behavior.
internal/fourslash/tests/gen/jsxAttributeSnippetCompletionUnclosed_test.go	Regenerated: pass snippet-enabled user preferences for JSX attribute snippet behavior.
internal/fourslash/tests/gen/jsxAttributeSnippetCompletionClosed_test.go	Regenerated: pass snippet-enabled user preferences for JSX attribute snippet behavior.
internal/fourslash/tests/gen/jsxAttributeSnippetCompletionAfterTypeArgs_test.go	Regenerated: pass snippet-enabled user preferences for JSX attribute snippet behavior.
internal/fourslash/tests/gen/jsxAttributeCompletionStyleNoSnippet_test.go	Regenerated: set preferences to explicitly disable snippet text.
internal/fourslash/tests/gen/jsxAttributeCompletionStyleNone_test.go	Regenerated: include snippet-text preference alongside `none` style.
internal/fourslash/tests/gen/jsxAttributeCompletionStyleDefault_test.go	Regenerated: include snippet-text preference.
internal/fourslash/tests/gen/jsxAttributeCompletionStyleBraces_test.go	Regenerated: include snippet-text preference and braces style.
internal/fourslash/tests/gen/jsxAttributeCompletionStyleAuto_test.go	Regenerated: include snippet-text preference and auto style.
internal/fourslash/tests/gen/importStatementCompletions_semicolons_test.go	New/regenerated: verify snippet import statement completions respect semicolon preference.
internal/fourslash/tests/gen/importStatementCompletions_quotes_test.go	New/regenerated: verify snippet import statement completions respect quote preference.
internal/fourslash/tests/gen/importStatementCompletions_pnpmTransitive_test.go	New/regenerated: verify import statement completions with pnpm transitive layout.
internal/fourslash/tests/gen/importStatementCompletions_pnpm1_test.go	New/regenerated: verify import statement completions with pnpm layout.
internal/fourslash/tests/gen/importStatementCompletions_noSnippet_test.go	New/regenerated: verify non-snippet import statement completion shape.
internal/fourslash/tests/gen/importStatementCompletions_noPatternAmbient_test.go	New/regenerated: verify pattern ambient modules are excluded from import statement completions.
internal/fourslash/tests/gen/importStatementCompletions_js2_test.go	New/regenerated: verify import statement completions in JS (variant).
internal/fourslash/tests/gen/importStatementCompletions_js_test.go	New/regenerated: verify import statement completions in JS.
internal/fourslash/tests/gen/importStatementCompletions_esModuleInterop2_test.go	New/regenerated: verify import statement completions with `esModuleInterop` (variant).
internal/fourslash/tests/gen/importStatementCompletions_esModuleInterop1_test.go	New/regenerated: verify import statement completions with `esModuleInterop`.
internal/fourslash/tests/gen/completionsOverridingProperties3_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingProperties2_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingProperties1_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethodDefaultExported_test.go	New/regenerated: validate class member stub completion with default-exported return types and import edits.
internal/fourslash/tests/gen/completionsOverridingMethodCrash2_test.go	New/regenerated: regression coverage for previous crash scenario with snippet class member completions.
internal/fourslash/tests/gen/completionsOverridingMethodCrash1_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod9_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod8_test.go	New/regenerated: validate class member snippet completion + apply code action updates.
internal/fourslash/tests/gen/completionsOverridingMethod7_test.go	New/regenerated: validate abstract overload completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod6_test.go	New/regenerated: validate modifier handling and excludes/includes across scenarios.
internal/fourslash/tests/gen/completionsOverridingMethod5_test.go	New/regenerated: validate abstract vs non-abstract stub generation.
internal/fourslash/tests/gen/completionsOverridingMethod4_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod3_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod22_test.go	New/regenerated: validate `$`-prefixed member completion with import edits.
internal/fourslash/tests/gen/completionsOverridingMethod21_test.go	New/regenerated: validate async modifier handling in overrides.
internal/fourslash/tests/gen/completionsOverridingMethod20_test.go	New/regenerated: validate completion when typing partial identifier with async modifier.
internal/fourslash/tests/gen/completionsOverridingMethod2_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod19_test.go	New/regenerated: validate robustness when non-modifier identifiers are present in modifier positions.
internal/fourslash/tests/gen/completionsOverridingMethod18_test.go	New/regenerated: validate decorator preservation in generated member stubs.
internal/fourslash/tests/gen/completionsOverridingMethod17_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod14_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod12_test.go	New/regenerated: validate accessor override stub completion for abstract/override scenarios.
internal/fourslash/tests/gen/completionsOverridingMethod11_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod10_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod1_test.go	Regenerated: set snippet preferences for class member snippet completion behavior.
internal/fourslash/tests/gen/completionsOverridingMethod0_test.go	New/regenerated: broad baseline coverage for override stub completions.
internal/fourslash/tests/gen/completionsObjectLiteralMethod5_test.go	New/regenerated: validate object-literal method snippet insertion + sortText ordering.
internal/fourslash/tests/gen/completionsObjectLiteralMethod4_test.go	New/regenerated: validate `this` parameter handling in object-literal method snippets.
internal/fourslash/tests/gen/completionsObjectLiteralMethod3_test.go	New/regenerated: validate union/intersection and optional member behavior for object-literal method snippets.
internal/fourslash/tests/gen/completionsObjectLiteralMethod2_test.go	New/regenerated: validate cross-file type references for object-literal method snippets.
internal/fourslash/tests/gen/completionsObjectLiteralMethod1_test.go	New/regenerated: validate overload/quoted names and labelDetails behavior for object-literal method snippets.
internal/fourslash/tests/gen/completionsJsxExpression_test.go	Regenerated: set snippet-text preference for JSX expression completions.
internal/fourslash/tests/gen/completionsClassMemberImportTypeNodeParameter4_test.go	Regenerated: set class member snippet preference for import-type-node cases.
internal/fourslash/tests/gen/completionsClassMemberImportTypeNodeParameter3_test.go	Regenerated: set class member snippet preference for import-type-node cases.
internal/fourslash/tests/gen/completionsClassMemberImportTypeNodeParameter2_test.go	Regenerated: set class member snippet preference for import-type-node cases.
internal/fourslash/tests/gen/completionsClassMemberImportTypeNodeParameter1_test.go	Regenerated: set class member snippet preference for import-type-node cases.
internal/fourslash/tests/gen/completionEntryClassMembersWithInferredFunctionReturnType1_test.go	Regenerated: set class member snippet preference for inferred return types.
internal/fourslash/tests/gen/completionCloneQuestionToken_test.go	Regenerated: set class member snippet preference for optional members.
internal/fourslash/tests/gen/completionClassMemberSnippetCrossFileNodeReuse1_test.go	New/regenerated: validate snippet generation without cross-file node reuse issues.
internal/fourslash/tests/gen/autoImportCompletionExportListAugmentation4_test.go	Regenerated: set class member snippet preference in auto-import augmentation scenarios.
internal/fourslash/tests/gen/autoImportCompletionExportListAugmentation3_test.go	Regenerated: set class member snippet preference in auto-import augmentation scenarios.
internal/fourslash/tests/gen/autoImportCompletionExportListAugmentation2_test.go	Regenerated: set class member snippet preference in auto-import augmentation scenarios.
internal/fourslash/tests/gen/autoImportCompletionExportListAugmentation1_test.go	Regenerated: set class member snippet preference in auto-import augmentation scenarios.
internal/fourslash/tests/gen/autoImportCompletionExportEqualsWithDefault1_test.go	Regenerated: set class member snippet preference for export-equals-with-default scenarios.
internal/fourslash/tests/gen/autoImportCompletionAmbientMergedModule1_test.go	Regenerated: set class member snippet preference for ambient merged module scenarios.

Files not reviewed (24)

internal/fourslash/tests/gen/autoImportCompletionAmbientMergedModule1_test.go: Language not supported
internal/fourslash/tests/gen/autoImportCompletionExportEqualsWithDefault1_test.go: Language not supported
internal/fourslash/tests/gen/autoImportCompletionExportListAugmentation1_test.go: Language not supported
internal/fourslash/tests/gen/autoImportCompletionExportListAugmentation2_test.go: Language not supported
internal/fourslash/tests/gen/autoImportCompletionExportListAugmentation3_test.go: Language not supported
internal/fourslash/tests/gen/autoImportCompletionExportListAugmentation4_test.go: Language not supported
internal/fourslash/tests/gen/completionClassMemberSnippetCrossFileNodeReuse1_test.go: Language not supported
internal/fourslash/tests/gen/completionCloneQuestionToken_test.go: Language not supported
internal/fourslash/tests/gen/completionEntryClassMembersWithInferredFunctionReturnType1_test.go: Language not supported
internal/fourslash/tests/gen/completionsClassMemberImportTypeNodeParameter1_test.go: Language not supported
internal/fourslash/tests/gen/completionsClassMemberImportTypeNodeParameter2_test.go: Language not supported
internal/fourslash/tests/gen/completionsClassMemberImportTypeNodeParameter3_test.go: Language not supported
internal/fourslash/tests/gen/completionsClassMemberImportTypeNodeParameter4_test.go: Language not supported
internal/fourslash/tests/gen/completionsJsxExpression_test.go: Language not supported
internal/fourslash/tests/gen/completionsObjectLiteralMethod1_test.go: Language not supported
internal/fourslash/tests/gen/completionsObjectLiteralMethod2_test.go: Language not supported
internal/fourslash/tests/gen/completionsObjectLiteralMethod3_test.go: Language not supported
internal/fourslash/tests/gen/completionsObjectLiteralMethod4_test.go: Language not supported
internal/fourslash/tests/gen/completionsObjectLiteralMethod5_test.go: Language not supported
internal/fourslash/tests/gen/completionsOverridingMethod0_test.go: Language not supported
internal/fourslash/tests/gen/completionsOverridingMethod10_test.go: Language not supported
internal/fourslash/tests/gen/completionsOverridingMethod11_test.go: Language not supported
internal/fourslash/tests/gen/completionsOverridingMethod12_test.go: Language not supported
internal/fourslash/tests/gen/completionsOverridingMethod14_test.go: Language not supported

…yuk/typescript-go into feat/completion-snippets

…o feat/completion-snippets

Copilot

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…o feat/completion-snippets

…yuk/typescript-go into feat/completion-snippets

gabritto · 2026-06-09T19:57:24Z


 func (f *missingMemberFixer) shouldAddOverrideKeyword(declaration *ast.Node) bool {
-	return declaration != nil && f.program.Options().NoImplicitOverride.IsTrue() && ast.HasAbstractModifier(declaration)
+	return declaration != nil && f.program.Options().NoImplicitOverride.IsTrue() && ast.IsClassElement(declaration)


Why do we need this?

TestCompletionsOverridingMethod1

Hmm, yeah, the original code seems wrong, but shouldn't we be checking that the declaration comes from a class? Since it could also come from an interface. I don't think IsClassElement does that, despite the name.

I've changed to check the parent class context

…o feat/completion-snippets

gabritto · 2026-06-10T18:29:37Z

+						originalSortText := core.OrElse(symbolToSortTextMap[symbolId], SortTextLocationPriority)
+						symbolToSortTextMap[symbolId] = ObjectLiteralPropertySortText(originalSortText, displayName)
+					}
+					entry := l.getEntryForObjectLiteralMethodCompletion(ctx, typeChecker, member, objectLikeContainer, file)


Shouldn't we opt out if we're in a JS file?

gabritto · 2026-06-10T18:48:44Z

+		NewLine:        core.GetNewLineKind(l.FormatOptions().NewLineCharacter),
+		Target:         l.GetProgram().Options().GetEmitScriptTarget(),
+	}, printer.PrintHandlers{}, nil /*emitContext*/)
+	return strings.TrimSuffix(signaturePrinter.Emit(methodSignature, file), ";")


Can you add a comment for a todo here? like // !!! OmitTrailingSemicolon printer option so we know this is a temporary thing because we don't have that option yet.

I added support for OmitTrailingSemicolon. Not sure if that’s appropriate for this PR, though.

gabritto · 2026-06-10T18:53:13Z

+}
+
+func (l *LanguageService) getEntryForObjectLiteralMethodCompletion(ctx context.Context, typeChecker *checker.Checker, symbol *ast.Symbol, enclosingDeclaration *ast.Node, file *ast.SourceFile) *symbolOriginInfoObjectLiteralMethod {
+	method := l.createObjectLiteralMethod(typeChecker, symbol, enclosingDeclaration, file)


I think related to my comment on skipping for JS files, we seem to be missing stuff that is in collectObjectLiteralMethodSymbols in Strada, like the isObjectLiteralMethodSymbol check.

gabritto · 2026-06-10T19:01:14Z

+	return factory.NewModifierList(nodes)
+}
+
+func addClassMemberSnippet(text string, newLine string) string {


I don't know that I like this. I may need to think about how we should do snippets in Corsa.

I added support for snippet elements and removed the string-based snippet normalization.

gabritto · 2026-06-10T19:03:17Z

+	}
+	view, err := l.getPreparedAutoImportView(file)
+	if err != nil {
+		view = l.getCurrentAutoImportView(file)


I think this needs to return an error, like we do for exhaustive case completions, so that we then redo the completion requests with the autoimport view.

…o feat/completion-snippets

feat: completion snippets

07b3ca6

a-tarasyuk force-pushed the feat/completion-snippets branch from f981cd0 to 07b3ca6 Compare May 18, 2026 13:33

a-tarasyuk added 2 commits May 18, 2026 20:48

Merge branch 'main' into feat/completion-snippets

a3cb242

Merge branch 'main' into feat/completion-snippets

04ad494

a-tarasyuk marked this pull request as ready for review May 18, 2026 20:35

Copilot AI review requested due to automatic review settings May 18, 2026 20:35

Copilot started reviewing on behalf of a-tarasyuk May 18, 2026 20:36 View session

Copilot AI reviewed May 18, 2026

View reviewed changes

Comment thread internal/ls/completions.go

a-tarasyuk added 3 commits May 19, 2026 09:46

align completion text edits with insert text

cbc395a

Merge branch 'feat/completion-snippets' of https://github.com/a-taras…

cc3578f

…yuk/typescript-go into feat/completion-snippets

Merge branch 'main' of https://github.com/microsoft/typescript-go int…

3684de9

…o feat/completion-snippets

a-tarasyuk requested a review from Copilot May 19, 2026 07:06

Copilot started reviewing on behalf of a-tarasyuk May 19, 2026 07:11 View session

Copilot AI reviewed May 19, 2026

DanielRosenwasser requested a review from gabritto May 19, 2026 22:02

Merge branch 'main' into feat/completion-snippets

b4486c9

a-tarasyuk closed this May 21, 2026

a-tarasyuk reopened this Jun 9, 2026

a-tarasyuk added 3 commits June 9, 2026 12:22

Merge branch 'main' of https://github.com/microsoft/typescript-go int…

9100426

…o feat/completion-snippets

Merge branch 'feat/completion-snippets' of https://github.com/a-taras…

c3fb785

…yuk/typescript-go into feat/completion-snippets

fix formatting

9565f47

gabritto reviewed Jun 9, 2026

View reviewed changes

Comment thread internal/checker/nodecopy.go Outdated

Comment thread internal/ls/lsutil/userpreferences.go Outdated

gabritto requested changes Jun 9, 2026

View reviewed changes

RyanCavanaugh added this to the Post-7.0 milestone Jun 9, 2026

a-tarasyuk added 4 commits June 10, 2026 00:07

add clientCapabilities support

a8302e0

remove ambient || abstract duplicates

c5ea81c

remove server-side completion capability test override

6fecd33

Merge branch 'main' of https://github.com/microsoft/typescript-go int…

6547140

…o feat/completion-snippets

a-tarasyuk requested a review from gabritto June 9, 2026 23:31

use scoped fourslash tests

24caea3

Merge branch 'main' of https://github.com/microsoft/typescript-go int…

b686dd4

…o feat/completion-snippets

a-tarasyuk force-pushed the feat/completion-snippets branch from effa665 to b686dd4 Compare June 10, 2026 10:01

a-tarasyuk added 5 commits June 10, 2026 13:07

fix script type error

4823a94

omit default capabilities options

cf28dfe

avoid marking reused import type qualifiers as synthesized

7a68430

check member parent before adding override modifier

60c60ef

cleanup

b67a7aa

gabritto reviewed Jun 10, 2026

View reviewed changes

a-tarasyuk added 8 commits June 10, 2026 22:29

handle auto import errors

003ac7a

match strada object literal method completion filtering

6b7d70b

add OmitTrailingSemicolon support

baa9497

add snippet tab stop element support

92b1243

add semicolon writer

1dc2704

fix formatting

1ce76e7

update tests

f70b1ad

update failing tests

172d9f7

a-tarasyuk requested a review from gabritto June 10, 2026 21:32

a-tarasyuk added 2 commits June 11, 2026 13:08

remove GetDefaultCapabilitiesWithSnippetSupport helper

95a04b5

add commitSemicolon

95ab86b

a-tarasyuk force-pushed the feat/completion-snippets branch 4 times, most recently from c1bed17 to 1871214 Compare July 3, 2026 18:17

a-tarasyuk added 2 commits July 4, 2026 08:59

Merge branch 'main' of https://github.com/microsoft/typescript-go int…

fc45531

…o feat/completion-snippets

update fourslash converter

cb13b5f

a-tarasyuk force-pushed the feat/completion-snippets branch from 1871214 to cb13b5f Compare July 4, 2026 06:02

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a-tarasyuk commented May 18, 2026 •

edited

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