add comments

Author: Emyrk

preview.go

@@ -68,18 +68,26 @@ func (o Output) MarshalJSON() ([]byte, error) {
 	})
 }
 
-// ValidatePresets will iterate over each preset, validate the inputs as a set,
-// and attach any diagnostics to the preset if there are issues.
-func ValidatePresets(ctx context.Context, input Input, preValid []types.Preset, dir fs.FS) {
+// ValidatePrebuilds will iterate over each preset, validate the inputs as a set,
+// and attach any diagnostics to the preset if there are issues. This must be done
+// because prebuilds have to be valid without user input.
+//
+// This will only validate presets that have prebuilds configured and have no existing
+// error diagnostics.
+func ValidatePrebuilds(ctx context.Context, input Input, preValid []types.Preset, dir fs.FS) []types.Preset {
 	for i := range preValid {
 		pre := &preValid[i]
 		if pre.Prebuild == nil || pre.Prebuild.Instances <= 0 {
 			// No prebuilds, so presets do not need to be valid without user input
 			continue
 		}
 
-		input.ParameterValues = pre.Parameters
+		if hcl.Diagnostics(pre.Diagnostics).HasErrors() {
+			// Piling on diagnostics is not helpful, if an error exists, leave it at that.
+			continue
+		}
 
+		input.ParameterValues = pre.Parameters
 		output, diagnostics := Preview(ctx, input, dir)
 		if diagnostics.HasErrors() {
 			pre.Diagnostics = append(pre.Diagnostics, diagnostics...)
@@ -102,6 +110,7 @@ func ValidatePresets(ctx context.Context, input Input, preValid []types.Preset,
 			}
 		}
 	}
+	return preValid
 }
 
 func Preview(ctx context.Context, input Input, dir fs.FS) (output *Output, diagnostics hcl.Diagnostics) {

preview_test.go

@@ -649,6 +649,9 @@ func Test_Extract(t *testing.T) {
 			}
 			require.False(t, diags.HasErrors())
 
+			// Validate prebuilds too
+			preview.ValidatePrebuilds(context.Background(), tc.input, output.Presets, dirFs)
+
 			if len(tc.warnings) > 0 {
 				for _, w := range tc.warnings {
 					idx := slices.IndexFunc(diags, func(diagnostic *hcl.Diagnostic) bool {
@@ -736,7 +739,7 @@ func TestPresetValidation(t *testing.T) {
 			require.False(t, diags.HasErrors())
 			require.Len(t, diags, 0)
 
-			preview.ValidatePresets(context.Background(), tc.input, output.Presets, dirFs)
+			preview.ValidatePrebuilds(context.Background(), tc.input, output.Presets, dirFs)
 			for _, preset := range output.Presets {
 				check, ok := tc.presetAssert[preset.Name]
 				require.True(t, ok, "unknown preset %s", preset.Name)