terraform: add tests for variables

terraform/context_apply_test.go

@@ -3,7 +3,6 @@ package terraform
 import (
 	"bytes"
 	"fmt"
-	"os"
 	"reflect"
 	"sort"
 	"strings"
@@ -4314,13 +4313,9 @@ func TestContext2Apply_vars(t *testing.T) {
 
 func TestContext2Apply_varsEnv(t *testing.T) {
 	// Set the env var
-	old_ami := tempEnv(t, "TF_VAR_ami", "baz")
-	old_list := tempEnv(t, "TF_VAR_list", `["Hello", "World"]`)
-	old_map := tempEnv(t, "TF_VAR_map", `{"Hello" = "World", "Foo" = "Bar", "Baz" = "Foo"}`)
-
-	defer os.Setenv("TF_VAR_ami", old_ami)
-	defer os.Setenv("TF_VAR_list", old_list)
-	defer os.Setenv("TF_VAR_list", old_map)
+	defer tempEnv(t, "TF_VAR_ami", "baz")()
+	defer tempEnv(t, "TF_VAR_list", `["Hello", "World"]`)()
+	defer tempEnv(t, "TF_VAR_map", `{"Hello" = "World", "Foo" = "Bar", "Baz" = "Foo"}`)()
 
 	m := testModule(t, "apply-vars-env")
 	p := testProvider("aws")

terraform/terraform_test.go

@@ -47,11 +47,12 @@ func tempDir(t *testing.T) string {
 }
 
 // tempEnv lets you temporarily set an environment variable. It returns
+// a function to defer to reset the old value.
 // the old value that should be set via a defer.
-func tempEnv(t *testing.T, k string, v string) string {
+func tempEnv(t *testing.T, k string, v string) func() {
 	old := os.Getenv(k)
 	os.Setenv(k, v)
-	return old
+	return func() { os.Setenv(k, old) }
 }
 
 func testConfig(t *testing.T, name string) *config.Config {

terraform/test-fixtures/vars-basic/main.tf

@@ -0,0 +1,14 @@
+variable "a" {
+    default = "foo"
+    type = "string"
+}
+
+variable "b" {
+    default = []
+    type = "list"
+}
+
+variable "c" {
+    default = {}
+    type = "map"
+}

terraform/variables_test.go

@@ -0,0 +1,114 @@
+package terraform
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestVariables(t *testing.T) {
+	cases := map[string]struct {
+		Module   string
+		Env      map[string]string
+		Override map[string]interface{}
+		Error    bool
+		Expected map[string]interface{}
+	}{
+		"config only": {
+			"vars-basic",
+			nil,
+			nil,
+			false,
+			map[string]interface{}{
+				"a": "foo",
+				"b": []interface{}{},
+				"c": map[string]interface{}{},
+			},
+		},
+
+		"env vars": {
+			"vars-basic",
+			map[string]string{
+				"TF_VAR_a": "bar",
+				"TF_VAR_b": `["foo", "bar"]`,
+				"TF_VAR_c": `{"foo" = "bar"}`,
+			},
+			nil,
+			false,
+			map[string]interface{}{
+				"a": "bar",
+				"b": []interface{}{"foo", "bar"},
+				"c": map[string]interface{}{
+					"foo": "bar",
+				},
+			},
+		},
+
+		"override": {
+			"vars-basic",
+			nil,
+			map[string]interface{}{
+				"a": "bar",
+				"b": []interface{}{"foo", "bar"},
+				"c": map[string]interface{}{
+					"foo": "bar",
+				},
+			},
+			false,
+			map[string]interface{}{
+				"a": "bar",
+				"b": []interface{}{"foo", "bar"},
+				"c": map[string]interface{}{
+					"foo": "bar",
+				},
+			},
+		},
+
+		"override partial map": {
+			"vars-basic",
+			map[string]string{
+				"TF_VAR_c": `{"foo" = "a", "bar" = "baz"}`,
+			},
+			map[string]interface{}{
+				"c": map[string]interface{}{
+					"foo": "bar",
+				},
+			},
+			false,
+			map[string]interface{}{
+				"a": "foo",
+				"b": []interface{}{},
+				"c": map[string]interface{}{
+					"foo": "bar",
+					"bar": "baz",
+				},
+			},
+		},
+	}
+
+	for name, tc := range cases {
+		if name != "override partial map" {
+			continue
+		}
+
+		// Wrapped in a func so we can get defers to work
+		func() {
+			// Set the env vars
+			for k, v := range tc.Env {
+				defer tempEnv(t, k, v)()
+			}
+
+			m := testModule(t, tc.Module)
+			actual, err := Variables(m, tc.Override)
+			if (err != nil) != tc.Error {
+				t.Fatalf("%s: err: %s", err)
+			}
+			if err != nil {
+				return
+			}
+
+			if !reflect.DeepEqual(actual, tc.Expected) {
+				t.Fatalf("%s: expected: %#v\n\ngot: %#v", name, tc.Expected, actual)
+			}
+		}()
+	}
+}