Fixing interpreting empty list as null value (#3317)

* fix: convert empty value to null value * chore: update test * chore: update test * chore: unit test improvements * chore: code improvements
gruntwork-io · Aug 2, 2024 · 8e8192a · 8e8192a
1 parent acbc58a
commit 8e8192a
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Showing 4 changed files with 76 additions and 11 deletions.
diff --git a/config/cty_helpers.go b/config/cty_helpers.go
@@ -333,24 +333,29 @@ func updateUnknownCtyValValues(value cty.Value) (cty.Value, error) {
 		for key, val := range mapVals {
 			val, err := updateUnknownCtyValValues(val)
 			if err != nil {
-				return cty.NilVal, errors.WithStackTrace(err)
+				return cty.NilVal, err
 			}
 			mapVals[key] = val
 		}
-		updatedValue = mapVals
+		if len(mapVals) > 0 {
+			updatedValue = mapVals
+		}
 
 	case value.Type().IsTupleType(), value.Type().IsListType():
 		sliceVals := value.AsValueSlice()
 		for key, val := range sliceVals {
 			val, err := updateUnknownCtyValValues(val)
 			if err != nil {
-				return cty.NilVal, errors.WithStackTrace(err)
+				return cty.NilVal, err
 			}
 			sliceVals[key] = val
 		}
-		updatedValue = sliceVals
+		if len(sliceVals) > 0 {
+			updatedValue = sliceVals
+		}
+	}
 
-	default:
+	if updatedValue == nil {
 		return value, nil
 	}
 

diff --git a/config/cty_helpers_test.go b/config/cty_helpers_test.go
@@ -0,0 +1,59 @@
+package config
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/zclconf/go-cty/cty"
+)
+
+func TestUpdateUnknownCtyValValues(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		value         cty.Value
+		expectedValue cty.Value
+	}{
+		{
+			cty.ListVal([]cty.Value{cty.ObjectVal(map[string]cty.Value{
+				"items": cty.ListVal([]cty.Value{cty.ObjectVal(map[string]cty.Value{
+					"firstname": cty.StringVal("joo"),
+					"lastname":  cty.UnknownVal(cty.String),
+				})}),
+			})}),
+			cty.ListVal([]cty.Value{cty.ObjectVal(map[string]cty.Value{
+				"items": cty.ListVal([]cty.Value{cty.ObjectVal(map[string]cty.Value{
+					"firstname": cty.StringVal("joo"),
+					"lastname":  cty.StringVal(""),
+				})}),
+			})}),
+		},
+		{
+			cty.ListVal([]cty.Value{cty.ObjectVal(map[string]cty.Value{})}),
+			cty.ListVal([]cty.Value{cty.ObjectVal(map[string]cty.Value{})}),
+		},
+		{
+			cty.ObjectVal(map[string]cty.Value{}),
+			cty.ObjectVal(map[string]cty.Value{}),
+		},
+		{
+			cty.ObjectVal(map[string]cty.Value{"key": cty.UnknownVal(cty.String)}),
+			cty.ObjectVal(map[string]cty.Value{"key": cty.StringVal("")}),
+		},
+	}
+
+	for i, testCase := range testCases {
+		testCase := testCase
+
+		t.Run(fmt.Sprintf("testCase-%d", i), func(t *testing.T) {
+			t.Parallel()
+
+			actualValue, err := updateUnknownCtyValValues(testCase.value)
+			require.NoError(t, err)
+
+			assert.Equal(t, testCase.expectedValue, actualValue)
+		})
+	}
+}
diff --git a/configstack/stack_test.go b/configstack/stack_test.go
@@ -301,7 +301,7 @@ func TestResolveTerraformModulesReadConfigFromParentConfig(t *testing.T) {
 		localsConfigs[name] = map[string]interface{}{
 			"dependencies":                  interface{}(nil),
 			"download_dir":                  "",
-			"generate":                      interface{}(nil),
+			"generate":                      map[string]interface{}{},
 			"iam_assume_role_duration":      interface{}(nil),
 			"iam_assume_role_session_name":  "",
 			"iam_role":                      "",

diff --git a/test/integration_test.go b/test/integration_test.go
@@ -3767,16 +3767,16 @@ func TestReadTerragruntConfigFull(t *testing.T) {
 	require.NoError(t, json.Unmarshal([]byte(outputs["dependencies"].Value.(string)), &depsOut))
 	assert.Equal(
 		t,
-		depsOut,
 		map[string]interface{}{
 			"paths": []interface{}{"../../fixture"},
 		},
+		depsOut,
 	)
+
 	generateOut := map[string]interface{}{}
 	require.NoError(t, json.Unmarshal([]byte(outputs["generate"].Value.(string)), &generateOut))
 	assert.Equal(
 		t,
-		generateOut,
 		map[string]interface{}{
 			"provider": map[string]interface{}{
 				"path":              "provider.tf",
@@ -3791,25 +3791,25 @@ func TestReadTerragruntConfigFull(t *testing.T) {
 `,
 			},
 		},
+		generateOut,
 	)
 	remoteStateOut := map[string]interface{}{}
 	require.NoError(t, json.Unmarshal([]byte(outputs["remote_state"].Value.(string)), &remoteStateOut))
 	assert.Equal(
 		t,
-		remoteStateOut,
 		map[string]interface{}{
 			"backend":                         "local",
 			"disable_init":                    false,
 			"disable_dependency_optimization": false,
 			"generate":                        map[string]interface{}{"path": "backend.tf", "if_exists": "overwrite_terragrunt"},
 			"config":                          map[string]interface{}{"path": "foo.tfstate"},
 		},
+		remoteStateOut,
 	)
 	terraformOut := map[string]interface{}{}
 	require.NoError(t, json.Unmarshal([]byte(outputs["terraformtg"].Value.(string)), &terraformOut))
 	assert.Equal(
 		t,
-		terraformOut,
 		map[string]interface{}{
 			"source":          "./delorean",
 			"include_in_copy": []interface{}{"time_machine.*"},
@@ -3845,8 +3845,9 @@ func TestReadTerragruntConfigFull(t *testing.T) {
 					"suppress_stdout": nil,
 				},
 			},
-			"error_hook": nil,
+			"error_hook": map[string]interface{}{},
 		},
+		terraformOut,
 	)
 }