test:add test of overload function definition

gopls/internal/lsp/source/definition_gox.go

@@ -80,7 +80,6 @@ func GopDefinition(ctx context.Context, snapshot Snapshot, fh FileHandle, positi
 
 	// The general case: the cursor is on an identifier.
 	_, obj, _ := gopReferencedObject(pkg, pgf, pos)
-
 	if obj == nil {
 		return nil, nil
 	}

gopls/internal/regtest/misc/definition_test.go

@@ -16,6 +16,111 @@ import (
 	"golang.org/x/tools/gopls/internal/lsp/tests/compare"
 )
 
+const overloadDefinition1 = `
+-- go.mod --
+module mod.com
+
+go 1.21.4
+-- def.gop --
+func add = (
+	func(a, b int) int {
+ 		return a + b
+   	}
+   	func(a, b string) string {
+   		return a + b
+   	}
+)
+-- test.gop --
+println add(100, 7)
+`
+
+const overloadDefinition2 = `
+-- go.mod --
+module mod.com
+
+go 1.21.4
+-- def.gop --
+func mulInt(a, b int) int {
+	return a * b
+}
+
+func mulFloat(a, b float64) float64 {
+	return a * b
+}
+
+func mul = (
+	mulInt
+	mulFloat
+)
+-- test.gop --
+println mul(100, 7)
+`
+
+const overloadDefinition3 = `
+-- go.mod --
+module mod.com
+
+go 1.21.4
+-- def.gop --
+type foo struct {
+}
+
+func (a *foo) mulInt(b int) *foo {
+	return a
+}
+
+func (a *foo) mulFoo(b *foo) *foo {
+	return a
+}
+
+func (foo).mul = (
+	(foo).mulInt
+	(foo).mulFoo
+)
+-- test.gop --
+var a *foo
+var c = a.mul(100)
+`
+
+func TestOverloadDefinition(t *testing.T) {
+	Run(t, overloadDefinition1, func(t *testing.T, env *Env) {
+		env.OpenFile("test.gop")
+		loc := env.GoToDefinition(env.RegexpSearch("test.gop", "add"))
+		name := env.Sandbox.Workdir.URIToPath(loc.URI)
+		if want := "def.gop"; name != want {
+			t.Errorf("GoToDefinition: got file %q, want %q", name, want)
+		}
+		// goxls : match the 'func' position of the corresponding overloaded function
+		if want := env.RegexpSearch("def.gop", `(func)\(a, b int\) int`); loc != want {
+			t.Errorf("GoToDefinition: got location %v, want %v", loc, want)
+		}
+	})
+	Run(t, overloadDefinition2, func(t *testing.T, env *Env) {
+		env.OpenFile("test.gop")
+		loc := env.GoToDefinition(env.RegexpSearch("test.gop", "mul"))
+		name := env.Sandbox.Workdir.URIToPath(loc.URI)
+		if want := "def.gop"; name != want {
+			t.Errorf("GoToDefinition: got file %q, want %q", name, want)
+		}
+		// goxls: match mulInt
+		if want := env.RegexpSearch("def.gop", `func (mulInt)\(a, b int\) int`); loc != want {
+			t.Errorf("GoToDefinition: got location %v, want %v", loc, want)
+		}
+	})
+	Run(t, overloadDefinition3, func(t *testing.T, env *Env) {
+		env.OpenFile("test.gop")
+		loc := env.GoToDefinition(env.RegexpSearch("test.gop", "mul"))
+		name := env.Sandbox.Workdir.URIToPath(loc.URI)
+		if want := "def.gop"; name != want {
+			t.Errorf("GoToDefinition: got file %q, want %q", name, want)
+		}
+		// goxls: match mulInt
+		if want := env.RegexpSearch("def.gop", `func \(a \*foo\) (mulInt)\(b int\) \*foo`); loc != want {
+			t.Errorf("GoToDefinition: got location %v, want %v", loc, want)
+		}
+	})
+}
+
 const internalDefinition = `
 -- go.mod --
 module mod.com