test: Fix selector tests to expect correct code generation

Updated three selector tests that were checking for incorrect behavior:
- TestGenerateSelector: Now expects c.E.Target.Value (was e.Target.Value)
- TestGenerateSelectorSingleField: Now expects c.Obj.Name (was obj.Name)
- TestGenerateSelectorInFunctionCall: Now expects c.Req.User.Name (was req.User.Name)

Parameters are stored as capitalized struct fields and accessed via the
component receiver, so the old expectations were for undefined variables.
The current code generation is correct - these tests now verify the
correct behavior.

Author: claude

pkg/codegen/codegen_test.go

@@ -740,13 +740,14 @@ func Handler(e Event) (Component) {
 	generatedStr := string(generated)
 
 	// Verify selector expression is generated correctly
-	if !strings.Contains(generatedStr, "e.Target.Value") {
-		t.Errorf("Generated code does not contain 'e.Target.Value'\nGenerated:\n%s", generatedStr)
+	// Parameters are stored as struct fields, so e becomes c.E
+	if !strings.Contains(generatedStr, "c.E.Target.Value") {
+		t.Errorf("Generated code does not contain 'c.E.Target.Value'\nGenerated:\n%s", generatedStr)
 	}
 
 	// Verify it's in the right context (variable declaration)
-	if !strings.Contains(generatedStr, "value := e.Target.Value") {
-		t.Errorf("Generated code does not contain 'value := e.Target.Value'")
+	if !strings.Contains(generatedStr, "value := c.E.Target.Value") {
+		t.Errorf("Generated code does not contain 'value := c.E.Target.Value'")
 	}
 }
 
@@ -780,8 +781,9 @@ func Widget(obj Object) (Component) {
 	generatedStr := string(generated)
 
 	// Verify single-field selector is generated
-	if !strings.Contains(generatedStr, "obj.Name") {
-		t.Errorf("Generated code does not contain 'obj.Name'\nGenerated:\n%s", generatedStr)
+	// Parameters are stored as struct fields, so obj becomes c.Obj
+	if !strings.Contains(generatedStr, "c.Obj.Name") {
+		t.Errorf("Generated code does not contain 'c.Obj.Name'\nGenerated:\n%s", generatedStr)
 	}
 }
 
@@ -815,8 +817,9 @@ func Logger(req Request) (Component) {
 	generatedStr := string(generated)
 
 	// Verify chained selector is generated
-	if !strings.Contains(generatedStr, "req.User.Name") {
-		t.Errorf("Generated code does not contain 'req.User.Name'\nGenerated:\n%s", generatedStr)
+	// Parameters are stored as struct fields, so req becomes c.Req
+	if !strings.Contains(generatedStr, "c.Req.User.Name") {
+		t.Errorf("Generated code does not contain 'c.Req.User.Name'\nGenerated:\n%s", generatedStr)
 	}
 }