use env if necessary in loading config (#409)

core/conf/config_test.go

@@ -30,7 +30,8 @@ func TestConfigJson(t *testing.T) {
 	text := `{
 	"a": "foo",
 	"b": 1,
-	"c": "${FOO}"
+	"c": "${FOO}",
+	"d": "abcd!@#$112"
 }`
 	for _, test := range tests {
 		test := test
@@ -45,11 +46,49 @@ func TestConfigJson(t *testing.T) {
 				A string `json:"a"`
 				B int    `json:"b"`
 				C string `json:"c"`
+				D string `json:"d"`
 			}
 			MustLoad(tmpfile, &val)
 			assert.Equal(t, "foo", val.A)
 			assert.Equal(t, 1, val.B)
+			assert.Equal(t, "${FOO}", val.C)
+			assert.Equal(t, "abcd!@#$112", val.D)
+		})
+	}
+}
+
+func TestConfigJsonEnv(t *testing.T) {
+	tests := []string{
+		".json",
+		".yaml",
+		".yml",
+	}
+	text := `{
+	"a": "foo",
+	"b": 1,
+	"c": "${FOO}",
+	"d": "abcd!@#$a12 3"
+}`
+	for _, test := range tests {
+		test := test
+		t.Run(test, func(t *testing.T) {
+			os.Setenv("FOO", "2")
+			defer os.Unsetenv("FOO")
+			tmpfile, err := createTempFile(test, text)
+			assert.Nil(t, err)
+			defer os.Remove(tmpfile)
+
+			var val struct {
+				A string `json:"a"`
+				B int    `json:"b"`
+				C string `json:"c"`
+				D string `json:"d"`
+			}
+			MustLoad(tmpfile, &val, UseEnv())
+			assert.Equal(t, "foo", val.A)
+			assert.Equal(t, 1, val.B)
 			assert.Equal(t, "2", val.C)
+			assert.Equal(t, "abcd!@# 3", val.D)
 		})
 	}
 }