Fix documentation inheritance for static method overrides on mixin intersection types (#3161)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: jakebailey <5341706+jakebailey@users.noreply.github.com>

Author: Copilot

internal/checker/exports.go

@@ -243,6 +243,14 @@ func (c *Checker) GetBaseTypes(t *Type) []*Type {
 	return c.getBaseTypes(t)
 }
 
+func (c *Checker) GetApparentType(t *Type) *Type {
+	return c.getApparentType(t)
+}
+
+func (c *Checker) GetBaseConstructorTypeOfClass(t *Type) *Type {
+	return c.getBaseConstructorTypeOfClass(t)
+}
+
 func (c *Checker) GetRestTypeOfSignature(sig *Signature) *Type {
 	return c.getRestTypeOfSignature(sig)
 }

internal/fourslash/tests/hoverMixinOverrideDocumentation_test.go

@@ -0,0 +1,38 @@
+package fourslash_test
+
+import (
+	"testing"
+
+	"github.com/microsoft/typescript-go/internal/fourslash"
+	"github.com/microsoft/typescript-go/internal/testutil"
+)
+
+func TestHoverMixinOverrideDocumentation(t *testing.T) {
+	t.Parallel()
+	defer testutil.RecoverAndFail(t, "Panic on fourslash test")
+
+	const content = `
+// @strict: true
+// @filename: main.ts
+
+declare class BaseClass {
+    /** some documentation */
+    static method(): number;
+}
+
+type AnyConstructor = abstract new (...args: any[]) => object
+
+class MixinClass {}
+declare function Mix<T extends AnyConstructor>(BaseClass: T): typeof MixinClass & T;
+
+declare class Mixed extends Mix(BaseClass) {
+    static method(): number;
+}
+
+Mixed./*1*/method;
+`
+	f, done := fourslash.NewFourslash(t, nil /*capabilities*/, content)
+	defer done()
+
+	f.VerifyQuickInfoAt(t, "1", "(method) Mixed.method(): number", "some documentation")
+}

internal/ls/hover.go

@@ -564,16 +564,25 @@ func getJSDocOrTag(c *checker.Checker, node *ast.Node) *ast.Node {
 		}
 		if ast.IsClassOrInterfaceLike(node.Parent) {
 			isStatic := ast.HasStaticModifier(node)
-			for _, baseType := range c.GetBaseTypes(c.GetDeclaredTypeOfSymbol(node.Parent.Symbol())) {
-				t := baseType
-				if isStatic && baseType.Symbol() != nil {
-					t = c.GetTypeOfSymbol(baseType.Symbol())
-				}
-				if prop := c.GetPropertyOfType(t, symbol.Name); prop != nil && prop.ValueDeclaration != nil {
+			classType := c.GetDeclaredTypeOfSymbol(node.Parent.Symbol())
+			if isStatic {
+				// For static members, use the checker's base constructor type resolution.
+				// This correctly handles intersection constructor types from mixins
+				// (e.g., typeof MixinClass & T) by preserving the full intersection.
+				staticBaseType := c.GetApparentType(c.GetBaseConstructorTypeOfClass(classType))
+				if prop := c.GetPropertyOfType(staticBaseType, symbol.Name); prop != nil && prop.ValueDeclaration != nil {
 					if jsDoc := getJSDocOrTag(c, prop.ValueDeclaration); jsDoc != nil {
 						return jsDoc
 					}
 				}
+			} else {
+				for _, baseType := range c.GetBaseTypes(classType) {
+					if prop := c.GetPropertyOfType(baseType, symbol.Name); prop != nil && prop.ValueDeclaration != nil {
+						if jsDoc := getJSDocOrTag(c, prop.ValueDeclaration); jsDoc != nil {
+							return jsDoc
+						}
+					}
+				}
 			}
 		}
 	}