test: use `T.Setenv` to set env vars in tests (#189)

This commit replaces `os.Setenv` with `t.Setenv` in tests. The
environment variable is automatically restored to its original value
when the test and all its subtests complete.

Reference: https://pkg.go.dev/testing#T.Setenv
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

pkg/app/app_test.go

@@ -637,8 +637,7 @@ releases:
 		{label: "name=doesnotexists", expectedReleases: []string{"zipkin", "prometheus", "grafana", "bar", "bar", "grafana", "postgresql"}, expectErr: false},
 	}
 
-	os.Setenv(envvar.Experimental, ExperimentalSelectorExplicit)
+	t.Setenv(envvar.Experimental, ExperimentalSelectorExplicit)
-	defer os.Unsetenv(envvar.Experimental)
 
 	runFilterSubHelmFilesTests(desiredTestcases, files, t, "2nd EmbeddedSelectors")
 
@@ -687,8 +686,7 @@ releases:
 		{label: "name!=grafana", expectedReleases: []string{"grafana", "zipkin", "mongodb"}, expectErr: false},
 	}
 
-	os.Setenv(envvar.Experimental, ExperimentalSelectorExplicit)
+	t.Setenv(envvar.Experimental, ExperimentalSelectorExplicit)
-	defer os.Unsetenv(envvar.Experimental)
 
 	runFilterSubHelmFilesTests(desiredTestcases, files, t, "2nd 3leveldeep")
 
@@ -749,8 +747,7 @@ releases:
 		{label: "select!=foo", expectedReleases: []string{"grafana", "prometheus", "zipkin", "prometheus", "zipkin", "mongodb"}, expectErr: false},
 	}
 
-	os.Setenv(envvar.Experimental, ExperimentalSelectorExplicit)
+	t.Setenv(envvar.Experimental, ExperimentalSelectorExplicit)
-	defer os.Unsetenv(envvar.Experimental)
 
 	runFilterSubHelmFilesTests(desiredTestcases, files, t, "2nd inherits")
 

pkg/app/constants_test.go

@@ -16,23 +16,20 @@ func TestIsExplicitSelectorInheritanceEnabled(t *testing.T) {
 	require.False(t, isExplicitSelectorInheritanceEnabled())
 
 	//check for env var ExperimentalEnvVar set to true
-	os.Setenv(envvar.Experimental, "true")
+	t.Setenv(envvar.Experimental, "true")
 	require.True(t, isExplicitSelectorInheritanceEnabled())
 
 	//check for env var ExperimentalEnvVar set to anything
-	os.Setenv(envvar.Experimental, "anything")
+	t.Setenv(envvar.Experimental, "anything")
 	require.False(t, isExplicitSelectorInheritanceEnabled())
 
 	//check for env var ExperimentalEnvVar set to ExperimentalSelectorExplicit
-	os.Setenv(envvar.Experimental, ExperimentalSelectorExplicit)
+	t.Setenv(envvar.Experimental, ExperimentalSelectorExplicit)
 	require.True(t, isExplicitSelectorInheritanceEnabled())
 
 	// check for env var ExperimentalEnvVar set to a string that contains ExperimentalSelectorExplicit and ExperimentalEnvVar set to true
-	os.Setenv(envvar.Experimental, fmt.Sprintf("%s-%s-%s", "a", ExperimentalSelectorExplicit, "b"))
+	t.Setenv(envvar.Experimental, fmt.Sprintf("%s-%s-%s", "a", ExperimentalSelectorExplicit, "b"))
 	require.True(t, isExplicitSelectorInheritanceEnabled())
-
-	// reset env var
-	defer os.Unsetenv(envvar.Experimental)
 }
 
 // TestExperimentalModeEnabled tests the experimentalModeEnabled function
@@ -42,13 +39,10 @@ func TestExperimentalModeEnabled(t *testing.T) {
 	require.False(t, experimentalModeEnabled())
 
 	//check for env var ExperimentalEnvVar set to anything
-	os.Setenv(envvar.Experimental, "anything")
+	t.Setenv(envvar.Experimental, "anything")
 	require.False(t, experimentalModeEnabled())
 
 	//check for env var ExperimentalEnvVar set to true
-	os.Setenv(envvar.Experimental, "true")
+	t.Setenv(envvar.Experimental, "true")
 	require.True(t, experimentalModeEnabled())
-
-	// reset env var
-	defer os.Unsetenv(envvar.Experimental)
 }

pkg/helmexec/context_test.go

@@ -94,11 +94,9 @@ func TestGetTillerlessEnv(t *testing.T) {
 		hc := &HelmContext{
 			Tillerless: test.tillerless,
 		}
-		os.Setenv(kubeconfigEnv, test.kubeconfig)
+		t.Setenv(kubeconfigEnv, test.kubeconfig)
 		result := hc.getTillerlessEnv()
 		require.Equalf(t, test.expected, result, "expected result %s, received result %s", test.expected, result)
 
 	}
-	defer os.Unsetenv(kubeconfigEnv)
-
 }

pkg/helmexec/exec_test.go

@@ -736,14 +736,13 @@ func Test_getTillerlessEnv(t *testing.T) {
 		t.Errorf("getTillerlessEnv() KUBECONFIG\nactual = %s\nexpect = nil", val)
 	}
 
-	os.Setenv("KUBECONFIG", "toto")
+	t.Setenv("KUBECONFIG", "toto")
 	actual = context.getTillerlessEnv()
 	cwd, _ := os.Getwd()
 	expected := path.Join(cwd, "toto")
 	if val, found := actual["KUBECONFIG"]; !found || val != expected {
 		t.Errorf("getTillerlessEnv() KUBECONFIG\nactual = %s\nexpect = %s", val, expected)
 	}
-	os.Unsetenv("KUBECONFIG")
 }
 
 func Test_mergeEnv(t *testing.T) {
@@ -795,13 +794,12 @@ func Test_IsHelm3(t *testing.T) {
 		t.Error("helmexec.IsHelm3() - Failed to detect Helm 3")
 	}
 
-	os.Setenv(envvar.Helm3, "1")
+	t.Setenv(envvar.Helm3, "1")
 	helm2Runner = mockRunner{output: []byte("Client: v2.16.0+ge13bc94\n")}
 	helm = New("helm", NewLogger(os.Stdout, "info"), "dev", &helm2Runner)
 	if !helm.IsHelm3() {
 		t.Errorf("helmexec.IsHelm3() - Helm3 not detected when %s is set", envvar.Helm3)
 	}
-	os.Setenv(envvar.Helm3, "")
 }
 
 func Test_GetVersion(t *testing.T) {

pkg/state/state_test.go

@@ -987,10 +987,7 @@ func TestHelmState_SyncRepos(t *testing.T) {
 		tt := tests[i]
 		t.Run(tt.name, func(t *testing.T) {
 			for k, v := range tt.envs {
-				err := os.Setenv(k, v)
+				t.Setenv(k, v)
-				if err != nil {
-					t.Error("HelmState.SyncRepos() could not set env var for testing")
-				}
 			}
 			state := &HelmState{
 				ReleaseSetSpec: ReleaseSetSpec{

pkg/tmpl/context_funcs_test.go

@@ -3,7 +3,6 @@ package tmpl
 import (
 	"encoding/json"
 	"fmt"
-	"os"
 	"path/filepath"
 	"reflect"
 	"testing"
@@ -286,7 +285,7 @@ func TestRequiredEnv(t *testing.T) {
 	require.Emptyf(t, envVal, "Expected empty string to be returned when environment variable %s is not set", envKey)
 
 	// test that the environment variable is set to an empty string
-	os.Setenv(envKey, "")
+	t.Setenv(envKey, "")
 	envVal, err = RequiredEnv(envKey)
 
 	require.NotNilf(t, err, "Expected error to be returned when environment variable %s is set to an empty string", envKey)
@@ -294,10 +293,8 @@ func TestRequiredEnv(t *testing.T) {
 
 	// test that the environment variable is set to a non-empty string
 	expected := "helmfile"
-	os.Setenv(envKey, expected)
+	t.Setenv(envKey, expected)
 
-	// Unset the environment variable
-	defer os.Unsetenv(envKey)
 	envVal, err = RequiredEnv(envKey)
 	require.Nilf(t, err, "Expected no error to be returned when environment variable %s is set to a non-empty string", envKey)
 	require.Equalf(t, expected, envVal, "Expected %s to be returned when environment variable %s is set to a non-empty string", expected, envKey)
@@ -348,8 +345,7 @@ func TestEnvExec(t *testing.T) {
 	require.Emptyf(t, output, "Expected empty string to be returned when executing command with no environment variables")
 
 	// test that the command is executed with os environment variables
-	os.Setenv(testKey, "foo")
+	t.Setenv(testKey, "foo")
-	defer os.Unsetenv(testKey)
 	output, err = ctx.EnvExec(nil, "bash", []interface{}{"-c", fmt.Sprintf("echo -n $%s", testKey)}, "")
 
 	require.Nilf(t, err, "Expected no error to be returned when executing command with environment variables")

pkg/tmpl/context_tmpl_test.go

@@ -2,7 +2,6 @@ package tmpl
 
 import (
 	"fmt"
-	"os"
 	"reflect"
 	"testing"
 )
@@ -234,10 +233,7 @@ func Test_renderTemplateToString(t *testing.T) {
 		tt := tests[i]
 		t.Run(tt.name, func(t *testing.T) {
 			for k, v := range tt.args.envs {
-				err := os.Setenv(k, v)
+				t.Setenv(k, v)
-				if err != nil {
-					t.Error("renderTemplateToString() could not set env var for testing")
-				}
 			}
 			got, err := renderTemplateToString(tt.args.s, tt.args.data)
 			if (err != nil) != tt.wantErr {

test/e2e/template/helmfile/tmpl_test.go

@@ -26,16 +26,9 @@ type tmplTestCase struct {
 }
 
 // setEnvs sets the environment variables for the test case
-func (t *tmplTestCase) setEnvs() {
+func (t *tmplTestCase) setEnvs(tt *testing.T) {
 	for k, v := range t.envs {
-		os.Setenv(k, v)
+		tt.Setenv(k, v)
-	}
-}
-
-// unSetEnvs unsets the environment variables for the test case
-func (t *tmplTestCase) unSetEnvs() {
-	for k := range t.envs {
-		os.Unsetenv(k)
 	}
 }
 
@@ -235,8 +228,7 @@ func TestTmplStrings(t *testing.T) {
 
 	for _, tc := range tmplE2eTest.tcs {
 		t.Run(tc.name, func(t *testing.T) {
-			tc.setEnvs()
+			tc.setEnvs(t)
-			defer tc.unSetEnvs()
 			tmpl, err := tmpl.Parse(tc.tmplString)
 			require.Nilf(t, err, "error parsing template: %v", err)