feat: support time.Location (#326)

* 1. Added support `time.Location`
2. Added minimal config [EditorConfig](https://editorconfig.org/)

* Added missing tests for parsing errors

* Corrected the method names

* I removed the editorconfig file so as not to confuse other developers with its presence.

* I removed the editorconfig file so as not to confuse other developers with its presence.

README.md

@@ -79,6 +79,7 @@ Complete list:
 - `uint8`
 - `uint`
 - `time.Duration`
+- `time.Location`
 - `encoding.TextUnmarshaler`
 - `url.URL`
 

env.go

@@ -87,21 +87,34 @@ var (
 
 func defaultTypeParsers() map[reflect.Type]ParserFunc {
 	return map[reflect.Type]ParserFunc{
-		reflect.TypeOf(url.URL{}): func(v string) (interface{}, error) {
-			u, err := url.Parse(v)
-			if err != nil {
-				return nil, newParseValueError("unable to parse URL", err)
-			}
-			return *u, nil
-		},
-		reflect.TypeOf(time.Nanosecond): func(v string) (interface{}, error) {
-			s, err := time.ParseDuration(v)
-			if err != nil {
-				return nil, newParseValueError("unable to parse duration", err)
-			}
-			return s, err
-		},
+		reflect.TypeOf(url.URL{}):       parseURL,
+		reflect.TypeOf(time.Nanosecond): parseDuration,
+		reflect.TypeOf(time.Location{}): parseLocation,
+	}
+}
+
+func parseURL(v string) (interface{}, error) {
+	u, err := url.Parse(v)
+	if err != nil {
+		return nil, newParseValueError("unable to parse URL", err)
+	}
+	return *u, nil
+}
+
+func parseDuration(v string) (interface{}, error) {
+	d, err := time.ParseDuration(v)
+	if err != nil {
+		return nil, newParseValueError("unable to parse duration", err)
+	}
+	return d, err
+}
+
+func parseLocation(v string) (interface{}, error) {
+	loc, err := time.LoadLocation(v)
+	if err != nil {
+		return nil, newParseValueError("unable to parse location", err)
 	}
+	return *loc, nil
 }
 
 // ParserFunc defines the signature of a function that can be used within

env_test.go

@@ -108,6 +108,11 @@ type Config struct {
 	DurationPtr  *time.Duration   `env:"DURATION"`
 	DurationPtrs []*time.Duration `env:"DURATIONS"`
 
+	Location     time.Location    `env:"LOCATION"`
+	Locations    []time.Location  `env:"LOCATIONS"`
+	LocationPtr  *time.Location   `env:"LOCATION"`
+	LocationPtrs []*time.Location `env:"LOCATIONS"`
+
 	Unmarshaler     unmarshaler    `env:"UNMARSHALER"`
 	UnmarshalerPtr  *unmarshaler   `env:"UNMARSHALER"`
 	Unmarshalers    []unmarshaler  `env:"UNMARSHALERS"`
@@ -118,7 +123,7 @@ type Config struct {
 	URLs    []url.URL  `env:"URLS"`
 	URLPtrs []*url.URL `env:"URLS"`
 
-	StringWithdefault string `env:"DATABASE_URL" envDefault:"postgres://localhost:5432/db"`
+	StringWithDefault string `env:"DATABASE_URL" envDefault:"postgres://localhost:5432/db"`
 
 	CustomSeparator []string `env:"SEPSTRINGS" envSeparator:":"`
 
@@ -254,6 +259,12 @@ func TestParsesEnv(t *testing.T) {
 	t.Setenv("DURATION", tos(duration1))
 	t.Setenv("DURATIONS", toss(duration1, duration2))
 
+	location1 := time.UTC
+	location2, errLoadLocation := time.LoadLocation("Europe/Berlin")
+	isNoErr(t, errLoadLocation)
+	t.Setenv("LOCATION", tos(location1))
+	t.Setenv("LOCATIONS", toss(location1, location2))
+
 	unmarshaler1 := unmarshaler{time.Minute}
 	unmarshaler2 := unmarshaler{time.Millisecond * 1232}
 	t.Setenv("UNMARSHALER", tos(unmarshaler1.Duration))
@@ -377,6 +388,13 @@ func TestParsesEnv(t *testing.T) {
 	isEqual(t, &duration1, cfg.DurationPtrs[0])
 	isEqual(t, &duration2, cfg.DurationPtrs[1])
 
+	isEqual(t, *location1, cfg.Location)
+	isEqual(t, location1, cfg.LocationPtr)
+	isEqual(t, *location1, cfg.Locations[0])
+	isEqual(t, *location2, cfg.Locations[1])
+	isEqual(t, location1, cfg.LocationPtrs[0])
+	isEqual(t, location2, cfg.LocationPtrs[1])
+
 	isEqual(t, unmarshaler1, cfg.Unmarshaler)
 	isEqual(t, &unmarshaler1, cfg.UnmarshalerPtr)
 	isEqual(t, unmarshaler1, cfg.Unmarshalers[0])
@@ -391,7 +409,7 @@ func TestParsesEnv(t *testing.T) {
 	isEqual(t, url1, cfg.URLPtrs[0].String())
 	isEqual(t, url2, cfg.URLPtrs[1].String())
 
-	isEqual(t, "postgres://localhost:5432/db", cfg.StringWithdefault)
+	isEqual(t, "postgres://localhost:5432/db", cfg.StringWithDefault)
 	isEqual(t, nonDefinedStr, cfg.NonDefined.String)
 	isEqual(t, nonDefinedStr, cfg.NestedNonDefined.NonDefined.String)
 
@@ -801,6 +819,20 @@ func TestInvalidDurations(t *testing.T) {
 	isTrue(t, errors.Is(err, ParseError{}))
 }
 
+func TestInvalidLocation(t *testing.T) {
+	t.Setenv("LOCATION", "should-be-a-valid-location")
+	err := Parse(&Config{})
+	isErrorWithMessage(t, err, `env: parse error on field "Location" of type "time.Location": unable to parse location: unknown time zone should-be-a-valid-location; parse error on field "LocationPtr" of type "*time.Location": unable to parse location: unknown time zone should-be-a-valid-location`)
+	isTrue(t, errors.Is(err, ParseError{}))
+}
+
+func TestInvalidLocations(t *testing.T) {
+	t.Setenv("LOCATIONS", "should-be-a-valid-location,UTC,Europe/Berlin")
+	err := Parse(&Config{})
+	isErrorWithMessage(t, err, `env: parse error on field "Locations" of type "[]time.Location": unable to parse location: unknown time zone should-be-a-valid-location; parse error on field "LocationPtrs" of type "[]*time.Location": unable to parse location: unknown time zone should-be-a-valid-location`)
+	isTrue(t, errors.Is(err, ParseError{}))
+}
+
 func TestParseStructWithoutEnvTag(t *testing.T) {
 	cfg := Config{}
 	isNoErr(t, Parse(&cfg))