From 7425227c9a95d08bee808aafcb864aa61694e64c Mon Sep 17 00:00:00 2001
From: Claire <213631+nyobe@users.noreply.github.com>
Date: Wed, 19 Feb 2025 10:41:04 -0800
Subject: [PATCH] Apply suggestions from code review

Co-authored-by: Pat Gavlin <pat@pulumi.com>
---
 ast/environment.go                                   | 2 +-
 ast/expr.go                                          | 7 ++++---
 ast/testdata/parse/invalid-invocation/expected.json  | 2 +-
 ast/testdata/parse/invalid-invocation2/expected.json | 2 +-
 4 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/ast/environment.go b/ast/environment.go
index 89cfe785..9ee598ca 100644
--- a/ast/environment.go
+++ b/ast/environment.go
@@ -129,7 +129,7 @@ func (d *MapDecl[T]) parse(name string, node syntax.Node) syntax.Diagnostics {
 		var v T
 		vname := name + "." + kvp.Key.Value()
 		if strings.HasPrefix(kvp.Key.Value(), "fn::") {
-			diags.Extend(syntax.NodeError(kvp.Key, "fn expression not allowed at the top level"))
+			diags.Extend(syntax.NodeError(kvp.Key, fmt.Sprintf("builtin function call %q not allowed at the top level", kvp.Key.Value())))
 		}
 		vdiags := parseNode(vname, &v, kvp.Value)
 		diags.Extend(vdiags...)
diff --git a/ast/expr.go b/ast/expr.go
index a1a9f61f..91b516c2 100644
--- a/ast/expr.go
+++ b/ast/expr.go
@@ -628,11 +628,12 @@ func tryParseFunction(node *syntax.ObjectNode) (Expr, syntax.Diagnostics, bool)
 	var diags syntax.Diagnostics
 	if node.Len() != 1 {
 		for i := 0; i < node.Len(); i++ {
-			if strings.HasPrefix(node.Index(i).Key.Value(), "fn::") {
-				diags = append(diags, syntax.NodeError(node, "fn:: expression must be the only key within object"))
-				return nil, diags, false
+			if k := node.Index(i).Key.Value(); strings.HasPrefix(k, "fn::") {
+				diags = append(diags, syntax.NodeError(node, fmt.Sprintf("illegal call to builtin function: %q must be the only key within its containing object", k)))
+
 			}
 		}
+		return nil, diags, false
 		return nil, nil, false
 	}
 
diff --git a/ast/testdata/parse/invalid-invocation/expected.json b/ast/testdata/parse/invalid-invocation/expected.json
index 2603b550..a46a3f07 100644
--- a/ast/testdata/parse/invalid-invocation/expected.json
+++ b/ast/testdata/parse/invalid-invocation/expected.json
@@ -53,7 +53,7 @@
     "diags": [
         {
             "Severity": 1,
-            "Summary": "fn:: expression must be the only key within object",
+            "Summary": "illegal call to builtin function: \"fn::rotate::provider\" must be the only key within its containing object",
             "Detail": "",
             "Subject": {
                 "Filename": "invalid-invocation",
diff --git a/ast/testdata/parse/invalid-invocation2/expected.json b/ast/testdata/parse/invalid-invocation2/expected.json
index ddc3b2e9..fe24a84c 100644
--- a/ast/testdata/parse/invalid-invocation2/expected.json
+++ b/ast/testdata/parse/invalid-invocation2/expected.json
@@ -18,7 +18,7 @@
     "diags": [
         {
             "Severity": 1,
-            "Summary": "fn expression not allowed at the top level",
+            "Summary": "builtin function call \"fn::secret\" not allowed at the top level",
             "Detail": "",
             "Subject": {
                 "Filename": "invalid-invocation2",