fix: show completion after class members with const assertion initializers (#2400)

Author: a-tarasyuk

internal/fourslash/tests/completionClassMembersAfterConstAssertionInitializer_test.go

@@ -0,0 +1,46 @@
+package fourslash_test
+
+import (
+	"testing"
+
+	"github.com/microsoft/typescript-go/internal/fourslash"
+	. "github.com/microsoft/typescript-go/internal/fourslash/tests/util"
+	"github.com/microsoft/typescript-go/internal/ls"
+	"github.com/microsoft/typescript-go/internal/lsp/lsproto"
+	"github.com/microsoft/typescript-go/internal/testutil"
+)
+
+func TestClassMembersAfterConstAssertionInitializer(t *testing.T) {
+	t.Parallel()
+	defer testutil.RecoverAndFail(t, "Panic on fourslash test")
+	const content = `
+interface A {
+	a: number
+	def: string
+}
+
+class B implements A {
+	a = 1 as const
+	/**/
+}
+`
+	f, done := fourslash.NewFourslash(t, nil /*capabilities*/, content)
+	defer done()
+
+	f.VerifyCompletions(t, "", &fourslash.CompletionsExpectedList{
+		IsIncomplete: false,
+		ItemDefaults: &fourslash.CompletionsExpectedItemDefaults{
+			CommitCharacters: &[]string{},
+			EditRange:        Ignored,
+		},
+		Items: &fourslash.CompletionsExpectedItems{
+			Exact: append([]fourslash.CompletionsExpectedItem{
+				&lsproto.CompletionItem{
+					Label:    "def",
+					Kind:     PtrTo(lsproto.CompletionItemKindField),
+					SortText: PtrTo(string(ls.SortTextLocationPriority)),
+				},
+			}, CompletionClassElementKeywords...),
+		},
+	})
+}

internal/ls/completions.go

@@ -4793,9 +4793,10 @@ func isSolelyIdentifierDefinitionLocation(
 		return ast.IsFunctionLike(parent) && !ast.IsMethodDeclaration(parent)
 	}
 
+	tokenKind := keywordForNode(contextToken)
 	// If the previous token is keyword corresponding to class member completion keyword
 	// there will be completion available here
-	if isClassMemberCompletionKeyword(keywordForNode(contextToken)) && isFromObjectTypeDeclaration(contextToken) {
+	if isClassMemberCompletionKeyword(tokenKind) && isFromObjectTypeDeclaration(contextToken) {
 		return false
 	}
 
@@ -4805,15 +4806,15 @@ func isSolelyIdentifierDefinitionLocation(
 		// - its name of the parameter and not being edited
 		// eg. constructor(a |<- this shouldnt show completion
 		if !ast.IsIdentifier(contextToken) ||
-			ast.IsParameterPropertyModifier(keywordForNode(contextToken)) ||
+			ast.IsParameterPropertyModifier(tokenKind) ||
 			isCurrentlyEditingNode(contextToken, file, position) {
 			return false
 		}
 	}
 
 	// Previous token may have been a keyword that was converted to an identifier.
 	switch keywordForNode(contextToken) {
-	case ast.KindAbstractKeyword, ast.KindClassKeyword, ast.KindConstKeyword, ast.KindDeclareKeyword,
+	case ast.KindAbstractKeyword, ast.KindClassKeyword, ast.KindDeclareKeyword,
 		ast.KindEnumKeyword, ast.KindFunctionKeyword, ast.KindInterfaceKeyword, ast.KindLetKeyword,
 		ast.KindPrivateKeyword, ast.KindProtectedKeyword, ast.KindPublicKeyword,
 		ast.KindStaticKeyword, ast.KindVarKeyword:
@@ -4848,7 +4849,9 @@ func isSolelyIdentifierDefinitionLocation(
 			return true
 		}
 	}
-
+	if tokenKind == ast.KindConstKeyword {
+		return true
+	}
 	return ast.IsDeclarationName(contextToken) &&
 		!ast.IsShorthandPropertyAssignment(parent) &&
 		!ast.IsJsxAttribute(parent) &&