Overwrite slice flag defaults when set

Closes #160

altsrc/flag.go

@@ -122,7 +122,7 @@ func (f *StringSliceFlag) ApplyInputSourceValue(context *cli.Context, isc InputS
 				return err
 			}
 			if value != nil {
-				var sliceValue cli.StringSlice = value
+				var sliceValue cli.StringSlice = *(cli.NewStringSlice(value...))
 				eachName(f.Name, func(name string) {
 					underlyingFlag := f.set.Lookup(f.Name)
 					if underlyingFlag != nil {
@@ -163,7 +163,7 @@ func (f *IntSliceFlag) ApplyInputSourceValue(context *cli.Context, isc InputSour
 				return err
 			}
 			if value != nil {
-				var sliceValue cli.IntSlice = value
+				var sliceValue cli.IntSlice = *(cli.NewIntSlice(value...))
 				eachName(f.Name, func(name string) {
 					underlyingFlag := f.set.Lookup(f.Name)
 					if underlyingFlag != nil {

flag.go

@@ -111,26 +111,39 @@ func (f GenericFlag) GetName() string {
 	return f.Name
 }
 
-// StringSlice is an opaque type for []string to satisfy flag.Value
+// StringSlice wraps a []string to satisfy flag.Value
-type StringSlice []string
+type StringSlice struct {
+	slice      []string
+	hasBeenSet bool
+}
+
+// NewStringSlice creates a *StringSlice with default values
+func NewStringSlice(defaults ...string) *StringSlice {
+	return &StringSlice{slice: append([]string{}, defaults...)}
+}
 
 // Set appends the string value to the list of values
 func (f *StringSlice) Set(value string) error {
-	*f = append(*f, value)
+	if !f.hasBeenSet {
+		f.slice = []string{}
+		f.hasBeenSet = true
+	}
+
+	f.slice = append(f.slice, value)
 	return nil
 }
 
 // String returns a readable representation of this value (for usage defaults)
 func (f *StringSlice) String() string {
-	return fmt.Sprintf("%s", *f)
+	return fmt.Sprintf("%s", f.slice)
 }
 
 // Value returns the slice of strings set by this flag
 func (f *StringSlice) Value() []string {
-	return *f
+	return f.slice
 }
 
-// StringSlice is a string flag that can be specified multiple times on the
+// StringSliceFlag is a string flag that can be specified multiple times on the
 // command-line
 type StringSliceFlag struct {
 	Name   string
@@ -163,10 +176,11 @@ func (f StringSliceFlag) Apply(set *flag.FlagSet) {
 		}
 	}
 
+	if f.Value == nil {
+		f.Value = &StringSlice{}
+	}
+
 	eachName(f.Name, func(name string) {
-		if f.Value == nil {
-			f.Value = &StringSlice{}
-		}
 		set.Var(f.Value, name, f.Usage)
 	})
 }
@@ -175,28 +189,51 @@ func (f StringSliceFlag) GetName() string {
 	return f.Name
 }
 
-// StringSlice is an opaque type for []int to satisfy flag.Value
+// IntSlice wraps an []int to satisfy flag.Value
-type IntSlice []int
+type IntSlice struct {
+	slice      []int
+	hasBeenSet bool
+}
+
+// NewIntSlice makes an *IntSlice with default values
+func NewIntSlice(defaults ...int) *IntSlice {
+	return &IntSlice{slice: append([]int{}, defaults...)}
+}
+
+// SetInt directly adds an integer to the list of values
+func (i *IntSlice) SetInt(value int) {
+	if !i.hasBeenSet {
+		i.slice = []int{}
+		i.hasBeenSet = true
+	}
+
+	i.slice = append(i.slice, value)
+}
 
 // Set parses the value into an integer and appends it to the list of values
-func (f *IntSlice) Set(value string) error {
+func (i *IntSlice) Set(value string) error {
+	if !i.hasBeenSet {
+		i.slice = []int{}
+		i.hasBeenSet = true
+	}
+
 	tmp, err := strconv.Atoi(value)
 	if err != nil {
 		return err
 	} else {
-		*f = append(*f, tmp)
+		i.slice = append(i.slice, tmp)
 	}
 	return nil
 }
 
 // String returns a readable representation of this value (for usage defaults)
-func (f *IntSlice) String() string {
+func (i *IntSlice) String() string {
-	return fmt.Sprintf("%d", *f)
+	return fmt.Sprintf("%v", i.slice)
 }
 
 // Value returns the slice of ints set by this flag
-func (f *IntSlice) Value() []int {
+func (i *IntSlice) Value() []int {
-	return *f
+	return i.slice
 }
 
 // IntSliceFlag is an int flag that can be specified multiple times on the

flag_test.go

@@ -4,9 +4,9 @@ import (
 	"fmt"
 	"os"
 	"reflect"
+	"runtime"
 	"strings"
 	"testing"
-	"runtime"
 )
 
 var boolFlagTests = []struct {
@@ -64,7 +64,7 @@ func TestStringFlagWithEnvVarHelpOutput(t *testing.T) {
 			expectedSuffix = " [%APP_FOO%]"
 		}
 		if !strings.HasSuffix(output, expectedSuffix) {
-			t.Errorf("%s does not end with" + expectedSuffix, output)
+			t.Errorf("%s does not end with"+expectedSuffix, output)
 		}
 	}
 }
@@ -74,30 +74,14 @@ var stringSliceFlagTests = []struct {
 	value    *StringSlice
 	expected string
 }{
-	{"help", func() *StringSlice {
+	{"help", NewStringSlice(""), "--help [--help option --help option]\t"},
-		s := &StringSlice{}
+	{"h", NewStringSlice(""), "-h [-h option -h option]\t"},
-		s.Set("")
+	{"h", NewStringSlice(""), "-h [-h option -h option]\t"},
-		return s
+	{"test", NewStringSlice("Something"), "--test [--test option --test option]\t"},
-	}(), "--help [--help option --help option]\t"},
+	{"d, dee", NewStringSlice("Inka", "Dinka", "dooo"), "-d, --dee [-d option -d option]\t"},
-	{"h", func() *StringSlice {
-		s := &StringSlice{}
-		s.Set("")
-		return s
-	}(), "-h [-h option -h option]\t"},
-	{"h", func() *StringSlice {
-		s := &StringSlice{}
-		s.Set("")
-		return s
-	}(), "-h [-h option -h option]\t"},
-	{"test", func() *StringSlice {
-		s := &StringSlice{}
-		s.Set("Something")
-		return s
-	}(), "--test [--test option --test option]\t"},
 }
 
 func TestStringSliceFlagHelpOutput(t *testing.T) {
-
 	for _, test := range stringSliceFlagTests {
 		flag := StringSliceFlag{Name: test.name, Value: test.value}
 		output := flag.String()
@@ -120,7 +104,7 @@ func TestStringSliceFlagWithEnvVarHelpOutput(t *testing.T) {
 			expectedSuffix = " [%APP_QWWX%]"
 		}
 		if !strings.HasSuffix(output, expectedSuffix) {
-			t.Errorf("%q does not end with" + expectedSuffix, output)
+			t.Errorf("%q does not end with"+expectedSuffix, output)
 		}
 	}
 }
@@ -157,7 +141,7 @@ func TestIntFlagWithEnvVarHelpOutput(t *testing.T) {
 			expectedSuffix = " [%APP_BAR%]"
 		}
 		if !strings.HasSuffix(output, expectedSuffix) {
-			t.Errorf("%s does not end with" + expectedSuffix, output)
+			t.Errorf("%s does not end with"+expectedSuffix, output)
 		}
 	}
 }
@@ -194,7 +178,7 @@ func TestDurationFlagWithEnvVarHelpOutput(t *testing.T) {
 			expectedSuffix = " [%APP_BAR%]"
 		}
 		if !strings.HasSuffix(output, expectedSuffix) {
-			t.Errorf("%s does not end with" + expectedSuffix, output)
+			t.Errorf("%s does not end with"+expectedSuffix, output)
 		}
 	}
 }
@@ -207,11 +191,7 @@ var intSliceFlagTests = []struct {
 	{"help", &IntSlice{}, "--help [--help option --help option]\t"},
 	{"h", &IntSlice{}, "-h [-h option -h option]\t"},
 	{"h", &IntSlice{}, "-h [-h option -h option]\t"},
-	{"test", func() *IntSlice {
+	{"test", NewIntSlice(9), "--test [--test option --test option]\t"},
-		i := &IntSlice{}
-		i.Set("9")
-		return i
-	}(), "--test [--test option --test option]\t"},
 }
 
 func TestIntSliceFlagHelpOutput(t *testing.T) {
@@ -238,7 +218,7 @@ func TestIntSliceFlagWithEnvVarHelpOutput(t *testing.T) {
 			expectedSuffix = " [%APP_SMURF%]"
 		}
 		if !strings.HasSuffix(output, expectedSuffix) {
-			t.Errorf("%q does not end with" + expectedSuffix, output)
+			t.Errorf("%q does not end with"+expectedSuffix, output)
 		}
 	}
 }
@@ -275,7 +255,7 @@ func TestFloat64FlagWithEnvVarHelpOutput(t *testing.T) {
 			expectedSuffix = " [%APP_BAZ%]"
 		}
 		if !strings.HasSuffix(output, expectedSuffix) {
-			t.Errorf("%s does not end with" + expectedSuffix, output)
+			t.Errorf("%s does not end with"+expectedSuffix, output)
 		}
 	}
 }
@@ -313,7 +293,7 @@ func TestGenericFlagWithEnvVarHelpOutput(t *testing.T) {
 			expectedSuffix = " [%APP_ZAP%]"
 		}
 		if !strings.HasSuffix(output, expectedSuffix) {
-			t.Errorf("%s does not end with" + expectedSuffix, output)
+			t.Errorf("%s does not end with"+expectedSuffix, output)
 		}
 	}
 }
@@ -404,6 +384,38 @@ func TestParseMultiStringSlice(t *testing.T) {
 	}).Run([]string{"run", "-s", "10", "-s", "20"})
 }
 
+func TestParseMultiStringSliceWithDefaults(t *testing.T) {
+	(&App{
+		Flags: []Flag{
+			StringSliceFlag{Name: "serve, s", Value: NewStringSlice("9", "2")},
+		},
+		Action: func(ctx *Context) {
+			if !reflect.DeepEqual(ctx.StringSlice("serve"), []string{"10", "20"}) {
+				t.Errorf("main name not set: %v", ctx.StringSlice("serve"))
+			}
+			if !reflect.DeepEqual(ctx.StringSlice("s"), []string{"10", "20"}) {
+				t.Errorf("short name not set: %v", ctx.StringSlice("s"))
+			}
+		},
+	}).Run([]string{"run", "-s", "10", "-s", "20"})
+}
+
+func TestParseMultiStringSliceWithDefaultsUnset(t *testing.T) {
+	(&App{
+		Flags: []Flag{
+			StringSliceFlag{Name: "serve, s", Value: NewStringSlice("9", "2")},
+		},
+		Action: func(ctx *Context) {
+			if !reflect.DeepEqual(ctx.StringSlice("serve"), []string{"9", "2"}) {
+				t.Errorf("main name not set: %v", ctx.StringSlice("serve"))
+			}
+			if !reflect.DeepEqual(ctx.StringSlice("s"), []string{"9", "2"}) {
+				t.Errorf("short name not set: %v", ctx.StringSlice("s"))
+			}
+		},
+	}).Run([]string{"run"})
+}
+
 func TestParseMultiStringSliceFromEnv(t *testing.T) {
 	os.Clearenv()
 	os.Setenv("APP_INTERVALS", "20,30,40")
@@ -423,6 +435,25 @@ func TestParseMultiStringSliceFromEnv(t *testing.T) {
 	}).Run([]string{"run"})
 }
 
+func TestParseMultiStringSliceFromEnvWithDefaults(t *testing.T) {
+	os.Clearenv()
+	os.Setenv("APP_INTERVALS", "20,30,40")
+
+	(&App{
+		Flags: []Flag{
+			StringSliceFlag{Name: "intervals, i", Value: NewStringSlice("1", "2", "5"), EnvVar: "APP_INTERVALS"},
+		},
+		Action: func(ctx *Context) {
+			if !reflect.DeepEqual(ctx.StringSlice("intervals"), []string{"20", "30", "40"}) {
+				t.Errorf("main name not set from env")
+			}
+			if !reflect.DeepEqual(ctx.StringSlice("i"), []string{"20", "30", "40"}) {
+				t.Errorf("short name not set from env")
+			}
+		},
+	}).Run([]string{"run"})
+}
+
 func TestParseMultiStringSliceFromEnvCascade(t *testing.T) {
 	os.Clearenv()
 	os.Setenv("APP_INTERVALS", "20,30,40")
@@ -442,6 +473,25 @@ func TestParseMultiStringSliceFromEnvCascade(t *testing.T) {
 	}).Run([]string{"run"})
 }
 
+func TestParseMultiStringSliceFromEnvCascadeWithDefaults(t *testing.T) {
+	os.Clearenv()
+	os.Setenv("APP_INTERVALS", "20,30,40")
+
+	(&App{
+		Flags: []Flag{
+			StringSliceFlag{Name: "intervals, i", Value: NewStringSlice("1", "2", "5"), EnvVar: "COMPAT_INTERVALS,APP_INTERVALS"},
+		},
+		Action: func(ctx *Context) {
+			if !reflect.DeepEqual(ctx.StringSlice("intervals"), []string{"20", "30", "40"}) {
+				t.Errorf("main name not set from env")
+			}
+			if !reflect.DeepEqual(ctx.StringSlice("i"), []string{"20", "30", "40"}) {
+				t.Errorf("short name not set from env")
+			}
+		},
+	}).Run([]string{"run"})
+}
+
 func TestParseMultiInt(t *testing.T) {
 	a := App{
 		Flags: []Flag{
@@ -531,6 +581,38 @@ func TestParseMultiIntSlice(t *testing.T) {
 	}).Run([]string{"run", "-s", "10", "-s", "20"})
 }
 
+func TestParseMultiIntSliceWithDefaults(t *testing.T) {
+	(&App{
+		Flags: []Flag{
+			IntSliceFlag{Name: "serve, s", Value: NewIntSlice(9, 2)},
+		},
+		Action: func(ctx *Context) {
+			if !reflect.DeepEqual(ctx.IntSlice("serve"), []int{10, 20}) {
+				t.Errorf("main name not set")
+			}
+			if !reflect.DeepEqual(ctx.IntSlice("s"), []int{10, 20}) {
+				t.Errorf("short name not set")
+			}
+		},
+	}).Run([]string{"run", "-s", "10", "-s", "20"})
+}
+
+func TestParseMultiIntSliceWithDefaultsUnset(t *testing.T) {
+	(&App{
+		Flags: []Flag{
+			IntSliceFlag{Name: "serve, s", Value: NewIntSlice(9, 2)},
+		},
+		Action: func(ctx *Context) {
+			if !reflect.DeepEqual(ctx.IntSlice("serve"), []int{9, 2}) {
+				t.Errorf("main name not set")
+			}
+			if !reflect.DeepEqual(ctx.IntSlice("s"), []int{9, 2}) {
+				t.Errorf("short name not set")
+			}
+		},
+	}).Run([]string{"run"})
+}
+
 func TestParseMultiIntSliceFromEnv(t *testing.T) {
 	os.Clearenv()
 	os.Setenv("APP_INTERVALS", "20,30,40")
@@ -550,6 +632,25 @@ func TestParseMultiIntSliceFromEnv(t *testing.T) {
 	}).Run([]string{"run"})
 }
 
+func TestParseMultiIntSliceFromEnvWithDefaults(t *testing.T) {
+	os.Clearenv()
+	os.Setenv("APP_INTERVALS", "20,30,40")
+
+	(&App{
+		Flags: []Flag{
+			IntSliceFlag{Name: "intervals, i", Value: NewIntSlice(1, 2, 5), EnvVar: "APP_INTERVALS"},
+		},
+		Action: func(ctx *Context) {
+			if !reflect.DeepEqual(ctx.IntSlice("intervals"), []int{20, 30, 40}) {
+				t.Errorf("main name not set from env")
+			}
+			if !reflect.DeepEqual(ctx.IntSlice("i"), []int{20, 30, 40}) {
+				t.Errorf("short name not set from env")
+			}
+		},
+	}).Run([]string{"run"})
+}
+
 func TestParseMultiIntSliceFromEnvCascade(t *testing.T) {
 	os.Clearenv()
 	os.Setenv("APP_INTERVALS", "20,30,40")