test(generators): add regression tests for deterministic ConfigMap key ordering

Adds explicit test cases to verify that ConfigMap data keys are always
emitted in sorted (alphabetical) order regardless of the order they are
defined in the source — covering literals, env files, and mixed sources.

Author: lolo1883NIG

api/internal/generators/configmap_test.go

@@ -42,6 +42,94 @@ func TestMakeConfigMap(t *testing.T) {
 		args types.ConfigMapArgs
 		exp  expected
 	}{
+		// Regression tests for https://github.com/kubernetes-sigs/kustomize/issues/4292
+		// ConfigMap data keys must be emitted in sorted (deterministic) order regardless
+		// of the order they are defined in the source.
+		"literal sources in non-alphabetical order produce sorted output": {
+			args: types.ConfigMapArgs{
+				GeneratorArgs: types.GeneratorArgs{
+					Name: "sortedLiterals",
+					KvPairSources: types.KvPairSources{
+						LiteralSources: []string{
+							"zebra=z",
+							"mango=m",
+							"apple=a",
+							"banana=b",
+							"kiwi=k",
+						},
+					},
+				},
+			},
+			exp: expected{
+				out: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: sortedLiterals
+data:
+  apple: a
+  banana: b
+  kiwi: k
+  mango: m
+  zebra: z
+`,
+			},
+		},
+		"env file with non-alphabetical keys produces sorted output": {
+			args: types.ConfigMapArgs{
+				GeneratorArgs: types.GeneratorArgs{
+					Name: "sortedEnv",
+					KvPairSources: types.KvPairSources{
+						EnvSources: []string{
+							filepath.Join("configmap", "unsorted.env"),
+						},
+					},
+				},
+			},
+			exp: expected{
+				out: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: sortedEnv
+data:
+  APPLE: a
+  BANANA: b
+  KIWI: k
+  MANGO: m
+  ZEBRA: z
+`,
+			},
+		},
+		"mixed literal and env sources produce sorted output": {
+			args: types.ConfigMapArgs{
+				GeneratorArgs: types.GeneratorArgs{
+					Name: "sortedMixed",
+					KvPairSources: types.KvPairSources{
+						LiteralSources: []string{
+							"zebra=z",
+							"apple=a",
+						},
+						EnvSources: []string{
+							filepath.Join("configmap", "unsorted.env"),
+						},
+					},
+				},
+			},
+			exp: expected{
+				out: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: sortedMixed
+data:
+  APPLE: a
+  BANANA: b
+  KIWI: k
+  MANGO: m
+  ZEBRA: z
+  apple: a
+  zebra: z
+`,
+			},
+		},
 		"construct config map from env": {
 			args: types.ConfigMapArgs{
 				GeneratorArgs: types.GeneratorArgs{
@@ -199,6 +287,10 @@ immutable: true
 	fSys.WriteFile(
 		filesys.RootedPath("configmap", "app.bin"),
 		manyHellos(30))
+	// unsorted.env is used by regression tests for issue #4292 (non-deterministic ordering)
+	fSys.WriteFile(
+		filesys.RootedPath("configmap", "unsorted.env"),
+		[]byte("ZEBRA=z\nMANGO=m\nAPPLE=a\nBANANA=b\nKIWI=k\n"))
 	kvLdr := kv.NewLoader(
 		loader.NewFileLoaderAtRoot(fSys),
 		valtest_test.MakeFakeValidator())