Make junitXMLTestReport output deterministic by iterating over a slic…

…e instead of a map, add test

internal/command/artifact/junit.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/xml"
 	"os"
+	"slices"
 	"strconv"
 	"strings"
 
@@ -98,7 +99,9 @@ func junitXMLTestReport(suite *moduletest.Suite) ([]byte, error) {
 	errorsName := xml.Name{Local: "errors"}
 
 	enc.EncodeToken(xml.StartElement{Name: suitesName})
-	for _, file := range suite.Files {
+
+	sortedFiles := suiteFilesAsSortedList(suite.Files) // to ensure consistent ordering in XML
+	for _, file := range sortedFiles {
 		// Each test file is modelled as a "test suite".
 
 		// First we'll count the number of tests and number of failures/errors
@@ -224,3 +227,19 @@ func junitXMLTestReport(suite *moduletest.Suite) ([]byte, error) {
 	enc.Close()
 	return buf.Bytes(), nil
 }
+
+func suiteFilesAsSortedList(files map[string]*moduletest.File) []*moduletest.File {
+	fileNames := make([]string, len(files))
+	i := 0
+	for k := range files {
+		fileNames[i] = k
+		i++
+	}
+	slices.Sort(fileNames)
+
+	sortedFiles := make([]*moduletest.File, len(files))
+	for i, name := range fileNames {
+		sortedFiles[i] = files[name]
+	}
+	return sortedFiles
+}

internal/command/artifact/junit_test.go

@@ -0,0 +1,92 @@
+package artifact
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform/internal/moduletest"
+)
+
+func Test_suiteFilesAsSortedList(t *testing.T) {
+	cases := map[string]struct {
+		Suite         *moduletest.Suite
+		ExpectedNames map[int]string
+	}{
+		"no test files": {
+			Suite: &moduletest.Suite{},
+		},
+		"3 test files ordered in map": {
+			Suite: &moduletest.Suite{
+				Status: moduletest.Skip,
+				Files: map[string]*moduletest.File{
+					"test_file_1.tftest.hcl": {
+						Name:   "test_file_1.tftest.hcl",
+						Status: moduletest.Skip,
+						Runs:   []*moduletest.Run{},
+					},
+					"test_file_2.tftest.hcl": {
+						Name:   "test_file_2.tftest.hcl",
+						Status: moduletest.Skip,
+						Runs:   []*moduletest.Run{},
+					},
+					"test_file_3.tftest.hcl": {
+						Name:   "test_file_3.tftest.hcl",
+						Status: moduletest.Skip,
+						Runs:   []*moduletest.Run{},
+					},
+				},
+			},
+			ExpectedNames: map[int]string{
+				0: "test_file_1.tftest.hcl",
+				1: "test_file_2.tftest.hcl",
+				2: "test_file_3.tftest.hcl",
+			},
+		},
+		"3 test files unordered in map": {
+			Suite: &moduletest.Suite{
+				Status: moduletest.Skip,
+				Files: map[string]*moduletest.File{
+					"test_file_3.tftest.hcl": {
+						Name:   "test_file_3.tftest.hcl",
+						Status: moduletest.Skip,
+						Runs:   []*moduletest.Run{},
+					},
+					"test_file_1.tftest.hcl": {
+						Name:   "test_file_1.tftest.hcl",
+						Status: moduletest.Skip,
+						Runs:   []*moduletest.Run{},
+					},
+					"test_file_2.tftest.hcl": {
+						Name:   "test_file_2.tftest.hcl",
+						Status: moduletest.Skip,
+						Runs:   []*moduletest.Run{},
+					},
+				},
+			},
+			ExpectedNames: map[int]string{
+				0: "test_file_1.tftest.hcl",
+				1: "test_file_2.tftest.hcl",
+				2: "test_file_3.tftest.hcl",
+			},
+		},
+	}
+
+	for tn, tc := range cases {
+		t.Run(tn, func(t *testing.T) {
+			list := suiteFilesAsSortedList(tc.Suite.Files)
+
+			if len(tc.ExpectedNames) != len(tc.Suite.Files) {
+				t.Fatalf("expected there to be %d items, got %d", len(tc.ExpectedNames), len(tc.Suite.Files))
+			}
+
+			if len(tc.ExpectedNames) == 0 {
+				return
+			}
+
+			for k, v := range tc.ExpectedNames {
+				if list[k].Name != v {
+					t.Fatalf("expected element %d in sorted list to be named %s, got %s", k, v, list[k].Name)
+				}
+			}
+		})
+	}
+}