cue: allow Value to be set at any path in Fill

Change-Id: I9f1df1c4bfde299ebb2914b573d7c4989fc64fe7
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/6460
Reviewed-by: CUE cueckoo <cueckoo@gmail.com>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>

cue/go.go

@@ -214,6 +214,12 @@ func convertRec(ctx *context, src source, nilIsTop bool, x interface{}) evaluate
 		}
 		return &nullLit{src.base()}
 
+	case Value:
+		if ctx.index != v.ctx().index {
+			panic("value of type Value is not created with same Runtime as Instance")
+		}
+		return v.eval(ctx)
+
 	case *ast.File:
 		x := newVisitorCtx(ctx, nil, nil, nil, false)
 		return ctx.manifest(x.walk(v))

cue/instance.go

@@ -334,15 +334,7 @@ func (inst *Instance) Fill(x interface{}, path ...string) (*Instance, error) {
 	for i := len(path) - 1; i >= 0; i-- {
 		x = map[string]interface{}{path[i]: x}
 	}
-	var value evaluated
-	if v, ok := x.(Value); ok {
-		if inst.index != v.ctx().index {
-			panic("value of type Value is not created with same Runtime as Instance")
-		}
-		value = v.eval(ctx)
-	} else {
-		value = convert(ctx, root, true, x)
-	}
+	value := convert(ctx, root, true, x)
 	eval := binOp(ctx, baseValue{}, opUnify, root, value)
 	// TODO: validate recursively?
 	err := inst.Err

cue/types.go

@@ -1596,15 +1596,7 @@ func (v Value) Fill(x interface{}, path ...string) Value {
 	for i := len(path) - 1; i >= 0; i-- {
 		x = map[string]interface{}{path[i]: x}
 	}
-	var value evaluated
-	if v, ok := x.(Value); ok {
-		if ctx.index != v.ctx().index {
-			panic("value of type Value is not created with same Runtime as Instance")
-		}
-		value = v.eval(ctx)
-	} else {
-		value = convert(ctx, root, true, x)
-	}
+	value := convert(ctx, root, true, x)
 	a := v.path.arc
 	a.v = mkBin(ctx, v.Pos(), opUnify, root, value)
 	a.cache = a.v.evalPartial(ctx)

cue/types_test.go

@@ -842,6 +842,34 @@ func TestFill(t *testing.T) {
 	}
 }
 
+func TestFill2(t *testing.T) {
+	r := &Runtime{}
+
+	root, err := r.Compile("test", `
+	#Provider: {
+		ID: string
+		notConcrete: bool
+	}
+	`)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	spec := root.LookupDef("#Provider")
+	providerInstance := spec.Fill("12345", "ID")
+	root, err = root.Fill(providerInstance, "providers", "myprovider")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	got := fmt.Sprint(root.Value())
+
+	if got != `{#Provider: C{ID: string, notConcrete: bool}, providers: {myprovider: C{ID: (string & "12345"), notConcrete: bool}}}` {
+		t.Error(got)
+	}
+}
+
 func TestValue_LookupDef(t *testing.T) {
 	r := &Runtime{}