cli/command/stack: TestConfigMergeInterpolation: various fixes

- Make the package-level configMergeTests local to the test itself.
- Rename fields to better describe intent
- Remove some redundant variables
- Reverse "expected" and "actual" fields for consistency
- Use assert.Check() to not fail early

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/stack/config_test.go

@@ -17,29 +17,30 @@ func TestConfigWithEmptyComposeFile(t *testing.T) {
 	assert.ErrorContains(t, cmd.Execute(), `Please specify a Compose file`)
 }
 
-var configMergeTests = []struct {
+func TestConfigMergeInterpolation(t *testing.T) {
+	tests := []struct {
 		name              string
 		skipInterpolation bool
-	first             string
-	second            string
-	merged            string
+		fileOne           string
+		fileTwo           string
+		expected          string
 	}{
 		{
 			name:              "With Interpolation",
 			skipInterpolation: false,
-		first: `version: "3.7"
+			fileOne: `version: "3.7"
 services:
   foo:
     image: busybox:latest
     command: cat file1.txt
 `,
-		second: `version: "3.7"
+			fileTwo: `version: "3.7"
 services:
   foo:
     image: busybox:${VERSION}
     command: cat file2.txt
 `,
-		merged: `version: "3.7"
+			expected: `version: "3.7"
 services:
   foo:
     command:
@@ -51,19 +52,19 @@ services:
 		{
 			name:              "Without Interpolation",
 			skipInterpolation: true,
-		first: `version: "3.7"
+			fileOne: `version: "3.7"
 services:
   foo:
     image: busybox:latest
     command: cat file1.txt
 `,
-		second: `version: "3.7"
+			fileTwo: `version: "3.7"
 services:
   foo:
     image: busybox:${VERSION}
     command: cat file2.txt
 `,
-		merged: `version: "3.7"
+			expected: `version: "3.7"
 services:
   foo:
     command:
@@ -74,31 +75,24 @@ services:
 		},
 	}
 
-func TestConfigMergeInterpolation(t *testing.T) {
-	for _, tt := range configMergeTests {
-		t.Run(tt.name, func(t *testing.T) {
-			firstConfig := []byte(tt.first)
-			secondConfig := []byte(tt.second)
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			firstConfigData, err := loader.ParseYAML([]byte(tc.fileOne))
+			assert.Check(t, err)
+			secondConfigData, err := loader.ParseYAML([]byte(tc.fileTwo))
+			assert.Check(t, err)
 
-			firstConfigData, err := loader.ParseYAML(firstConfig)
-			assert.NilError(t, err)
-			secondConfigData, err := loader.ParseYAML(secondConfig)
-			assert.NilError(t, err)
-
-			env := map[string]string{
-				"VERSION": "1.0",
-			}
-
-			cfg, err := outputConfig(composetypes.ConfigDetails{
+			actual, err := outputConfig(composetypes.ConfigDetails{
 				ConfigFiles: []composetypes.ConfigFile{
 					{Config: firstConfigData, Filename: "firstConfig"},
 					{Config: secondConfigData, Filename: "secondConfig"},
 				},
-				Environment: env,
-			}, tt.skipInterpolation)
-			assert.NilError(t, err)
-
-			assert.Equal(t, cfg, tt.merged)
+				Environment: map[string]string{
+					"VERSION": "1.0",
+				},
+			}, tc.skipInterpolation)
+			assert.Check(t, err)
+			assert.Equal(t, tc.expected, actual)
 		})
 	}
 }