Merge pull request #3 from DataDog/xavier.lucas/get-with-errors

Expose type casting errors

util.go

@@ -146,16 +146,17 @@ func userHomeDir() string {
 	return os.Getenv("HOME")
 }
 
-func safeMul(a, b uint) uint {
+func safeMul(a, b uint) (uint, error) {
 	c := a * b
 	if a > 1 && b > 1 && c/b != a {
-		return 0
+		return 0, fmt.Errorf("multiplication overflows uint: %d*%d", a, b)
 	}
-	return c
+	return c, nil
 }
 
 // parseSizeInBytes converts strings like 1GB or 12 mb into an unsigned integer number of bytes
-func parseSizeInBytes(sizeStr string) uint {
+func parseSizeInBytes(sizeStr string) (uint, error) {
+	rawStr := sizeStr
 	sizeStr = strings.TrimSpace(sizeStr)
 	lastChar := len(sizeStr) - 1
 	multiplier := uint(1)
@@ -181,12 +182,17 @@ func parseSizeInBytes(sizeStr string) uint {
 		}
 	}
 
-	size := cast.ToInt(sizeStr)
-	if size < 0 {
-		size = 0
+	num, err := cast.ToUintE(sizeStr)
+	if err != nil {
+		return 0, err
 	}
 
-	return safeMul(uint(size), multiplier)
+	size, err := safeMul(num, multiplier)
+	if err != nil {
+		return 0, fmt.Errorf("unable to cast %q to uint: %s", rawStr, err)
+	}
+
+	return size, nil
 }
 
 // deepSearch scans deep maps, following the key indexes listed in the

viper.go

@@ -726,77 +726,162 @@ func (v *Viper) GetString(key string) string {
 	return cast.ToString(v.Get(key))
 }
 
+// GetStringE is the same than GetString but also returns parsing errors.
+func GetStringE(key string) (string, error) { return v.GetStringE(key) }
+func (v *Viper) GetStringE(key string) (string, error) {
+	return cast.ToStringE(v.Get(key))
+}
+
 // GetBool returns the value associated with the key as a boolean.
 func GetBool(key string) bool { return v.GetBool(key) }
 func (v *Viper) GetBool(key string) bool {
 	return cast.ToBool(v.Get(key))
 }
 
+// GetBoolE is the same than GetBool but also returns parsing errors.
+func GetBoolE(key string) (bool, error) { return v.GetBoolE(key) }
+func (v *Viper) GetBoolE(key string) (bool, error) {
+	return cast.ToBoolE(v.Get(key))
+}
+
 // GetInt returns the value associated with the key as an integer.
 func GetInt(key string) int { return v.GetInt(key) }
 func (v *Viper) GetInt(key string) int {
 	return cast.ToInt(v.Get(key))
 }
 
+// GetIntE is the same than GetInt but also returns parsing errors.
+func GetIntE(key string) (int, error) { return v.GetIntE(key) }
+func (v *Viper) GetIntE(key string) (int, error) {
+	return cast.ToIntE(v.Get(key))
+}
+
 // GetInt32 returns the value associated with the key as an integer.
 func GetInt32(key string) int32 { return v.GetInt32(key) }
 func (v *Viper) GetInt32(key string) int32 {
 	return cast.ToInt32(v.Get(key))
 }
 
+// GetInt32E is the same than GetInt32 but also returns parsing errors.
+func GetInt32E(key string) (int32, error) { return v.GetInt32E(key) }
+func (v *Viper) GetInt32E(key string) (int32, error) {
+	return cast.ToInt32E(v.Get(key))
+}
+
 // GetInt64 returns the value associated with the key as an integer.
 func GetInt64(key string) int64 { return v.GetInt64(key) }
 func (v *Viper) GetInt64(key string) int64 {
 	return cast.ToInt64(v.Get(key))
 }
 
+// GetInt64E is the same than GetInt64 but also returns parsing errors.
+func GetInt64E(key string) (int64, error) { return v.GetInt64E(key) }
+func (v *Viper) GetInt64E(key string) (int64, error) {
+	return cast.ToInt64E(v.Get(key))
+}
+
 // GetFloat64 returns the value associated with the key as a float64.
 func GetFloat64(key string) float64 { return v.GetFloat64(key) }
 func (v *Viper) GetFloat64(key string) float64 {
 	return cast.ToFloat64(v.Get(key))
 }
 
+// GetFloat64E is the same than GetFloat64 but also returns parsing errors.
+func GetFloat64E(key string) (float64, error) { return v.GetFloat64E(key) }
+func (v *Viper) GetFloat64E(key string) (float64, error) {
+	return cast.ToFloat64E(v.Get(key))
+}
+
 // GetTime returns the value associated with the key as time.
 func GetTime(key string) time.Time { return v.GetTime(key) }
 func (v *Viper) GetTime(key string) time.Time {
 	return cast.ToTime(v.Get(key))
 }
 
+// GetTimeE is the same than GetTime but also returns parsing errors.
+func GetTimeE(key string) (time.Time, error) { return v.GetTimeE(key) }
+func (v *Viper) GetTimeE(key string) (time.Time, error) {
+	return cast.ToTimeE(v.Get(key))
+}
+
 // GetDuration returns the value associated with the key as a duration.
 func GetDuration(key string) time.Duration { return v.GetDuration(key) }
 func (v *Viper) GetDuration(key string) time.Duration {
 	return cast.ToDuration(v.Get(key))
 }
 
+// GetDurationE is the same than GetDuration but also returns parsing errors.
+func GetDurationE(key string) (time.Duration, error) { return v.GetDurationE(key) }
+func (v *Viper) GetDurationE(key string) (time.Duration, error) {
+	return cast.ToDurationE(v.Get(key))
+}
+
 // GetStringSlice returns the value associated with the key as a slice of strings.
 func GetStringSlice(key string) []string { return v.GetStringSlice(key) }
 func (v *Viper) GetStringSlice(key string) []string {
 	return cast.ToStringSlice(v.Get(key))
 }
 
+// GetStringSliceE is the same than GetStringSlice but also returns parsing errors.
+func GetStringSliceE(key string) ([]string, error) { return v.GetStringSliceE(key) }
+func (v *Viper) GetStringSliceE(key string) ([]string, error) {
+	return cast.ToStringSliceE(v.Get(key))
+}
+
 // GetStringMap returns the value associated with the key as a map of interfaces.
 func GetStringMap(key string) map[string]interface{} { return v.GetStringMap(key) }
 func (v *Viper) GetStringMap(key string) map[string]interface{} {
 	return cast.ToStringMap(v.Get(key))
 }
 
+// GetStringMapE is the same than GetStringMap but also returns parsing errors.
+func GetStringMapE(key string) (map[string]interface{}, error) { return v.GetStringMapE(key) }
+func (v *Viper) GetStringMapE(key string) (map[string]interface{}, error) {
+	return cast.ToStringMapE(v.Get(key))
+}
+
 // GetStringMapString returns the value associated with the key as a map of strings.
 func GetStringMapString(key string) map[string]string { return v.GetStringMapString(key) }
 func (v *Viper) GetStringMapString(key string) map[string]string {
 	return cast.ToStringMapString(v.Get(key))
 }
 
+// GetStringMapStringE is the same than GetStringMapString but also returns parsing errors.
+func GetStringMapStringE(key string) (map[string]string, error) { return v.GetStringMapStringE(key) }
+func (v *Viper) GetStringMapStringE(key string) (map[string]string, error) {
+	return cast.ToStringMapStringE(v.Get(key))
+}
+
 // GetStringMapStringSlice returns the value associated with the key as a map to a slice of strings.
 func GetStringMapStringSlice(key string) map[string][]string { return v.GetStringMapStringSlice(key) }
 func (v *Viper) GetStringMapStringSlice(key string) map[string][]string {
 	return cast.ToStringMapStringSlice(v.Get(key))
 }
 
+// GetStringMapStringSliceE is the same than GetStringMapStringSlice but also returns parsing errors.
+func GetStringMapStringSliceE(key string) (map[string][]string, error) {
+	return v.GetStringMapStringSliceE(key)
+}
+func (v *Viper) GetStringMapStringSliceE(key string) (map[string][]string, error) {
+	return cast.ToStringMapStringSliceE(v.Get(key))
+}
+
 // GetSizeInBytes returns the size of the value associated with the given key
 // in bytes.
 func GetSizeInBytes(key string) uint { return v.GetSizeInBytes(key) }
 func (v *Viper) GetSizeInBytes(key string) uint {
 	sizeStr := cast.ToString(v.Get(key))
+	size, _ := parseSizeInBytes(sizeStr)
+	return size
+}
+
+// GetSizeInBytesE is the same than GetSizeInBytes but also returns parsing errors.
+func GetSizeInBytesE(key string) (uint, error) { return v.GetSizeInBytesE(key) }
+func (v *Viper) GetSizeInBytesE(key string) (uint, error) {
+	sizeStr, err := cast.ToStringE(v.Get(key))
+	if err != nil {
+		return 0, err
+	}
 	return parseSizeInBytes(sizeStr)
 }
 

viper_test.go

@@ -735,19 +735,24 @@ func TestBoundCaseSensitivity(t *testing.T) {
 }
 
 func TestSizeInBytes(t *testing.T) {
-	input := map[string]uint{
-		"":               0,
-		"b":              0,
-		"12 bytes":       0,
-		"200000000000gb": 0,
-		"12 b":           12,
-		"43 MB":          43 * (1 << 20),
-		"10mb":           10 * (1 << 20),
-		"1gb":            1 << 30,
+	input := map[string]struct {
+		Size  uint
+		Error bool
+	}{
+		"":               {0, true},
+		"b":              {0, true},
+		"12 bytes":       {0, true},
+		"200000000000gb": {0, true},
+		"12 b":           {12, false},
+		"43 MB":          {43 * (1 << 20), false},
+		"10mb":           {10 * (1 << 20), false},
+		"1gb":            {1 << 30, false},
 	}
 
 	for str, expected := range input {
-		assert.Equal(t, expected, parseSizeInBytes(str), str)
+		size, err := parseSizeInBytes(str)
+		assert.Equal(t, expected.Size, size, str)
+		assert.Equal(t, expected.Error, err != nil, str)
 	}
 }