CliParser.Init() accepts optional flags. Currently una flag is available: ResetOnEqualSign

cli.go

@@ -14,6 +14,7 @@ type cliParser interface {
 	getCliArgs(startIndex, endIndex int) (args []string)
 	PrintVersion(specs []string)
 	PrintUsage()
+	FlagIsSet(flag int16) bool
 }
 
 type cliOptionParser interface {
@@ -25,7 +26,7 @@ type cliOptionParser interface {
 	isSet() bool
 	isHidden() bool
 	requiresValue() bool
-	finalCheck(cliValue string) (err error)
+	finalCheck() (err error)
 }
 
 type OptManager interface {
@@ -33,7 +34,7 @@ type OptManager interface {
 }
 
 type SpecialValueFunc func(manager OptManager, cliValue string, currentValue any) (value any, err error)
-type FinalCheckFunc func(cliValue string, currentValue any) (err error)
+type FinalCheckFunc func(currentValue any) (err error)
 
 type OptReference interface {
 	AddSpecialValue(cliValue string, specialFunc SpecialValueFunc)
@@ -41,20 +42,31 @@ type OptReference interface {
 	SetHidden(hidden bool)
 }
 
+const (
+	ResetOnEqualSign = int16(1 << iota) // for some option types, like arrays, the equal signs reset to empty the accumulator of values
+)
+
 type CliParser struct {
 	description string
 	version     string
 	options     []cliOptionParser
 	argSpecs    []argSpec
 	cliArgs     []string
+	flags       int16
 }
 
-func (cli *CliParser) Init(argv []string, version string, description string) {
+func (cli *CliParser) Init(argv []string, version string, description string, flags ...int16) {
 	cli.version = version
 	cli.description = description
 	cli.cliArgs = argv
+	for _, flag := range flags {
+		cli.flags |= flag
+	}
 }
 
+func (cli *CliParser) FlagIsSet(flag int16) bool {
+	return (cli.flags & flag) == flag
+}
 func (cli *CliParser) GetOption(name string) (ref OptReference) {
 	var opt cliOptionParser
 	if strings.HasPrefix(name, "-") {
@@ -158,17 +170,12 @@ func (cli *CliParser) addHelpAndVersion() {
 
 }
 
-func (cli *CliParser) Parse() (err error) {
-	var arg string
-	var i int
-	var args []string
+func (cli *CliParser) parseOptions() (commandArgs []string, err error) {
+	// var commandArgs []string
 	var optionsAllowed bool = true
 
-	cli.addHelpAndVersion()
-
-	// first parse options and collect argument in the args array
 	skipNext := false
-	for i, arg = range cli.cliArgs[1:] {
+	for i, arg := range cli.cliArgs[1:] {
 		if skipNext {
 			skipNext = false
 		} else {
@@ -182,50 +189,79 @@ func (cli *CliParser) Parse() (err error) {
 					break
 				}
 			} else {
-				args = append(args, arg)
+				commandArgs = append(commandArgs, arg)
 			}
 		}
 	}
+	return
+}
+
+func (cli *CliParser) checkOptionValues() (err error) {
+	for _, opt := range cli.options {
+		if err = opt.finalCheck(); err != nil {
+			break
+		}
+	}
+	return
+}
+
+func (cli *CliParser) parseCommandArgs(commandArgs []string) (err error) {
+	var n int
+
+	i := 0
+	// acquire arguments as required by the argSpecs
+	specIndex := -1
+	for index, argSpec := range cli.argSpecs {
+		specIndex = index
+		if n, err = argSpec.parse(cli, specIndex, commandArgs, i); err != nil {
+			break
+		}
+		i += n
+		if i >= len(commandArgs) {
+			break
+		}
+	}
+
+	// check if there are remaining arg-specs that require a value
+	if err == nil {
+		if i < len(commandArgs) {
+			err = fmt.Errorf("too many arguments: %d allowed", i)
+		} else {
+			specIndex++
+			if specIndex < len(cli.argSpecs) {
+				// skip all non required args
+				for _, spec := range cli.argSpecs[specIndex:] {
+					if !spec.getBase().required {
+						specIndex++
+					}
+				}
+			}
+			// return error if there are remaining arg-specs that require a value
+			if specIndex < len(cli.argSpecs) {
+				err = errTooFewArguments(len(cli.argSpecs))
+			}
+		}
+	}
+	return
+}
+
+func (cli *CliParser) Parse() (err error) {
+	var commandArgs []string
+
+	cli.addHelpAndVersion()
+
+	// first parse options and collect command arguments in the args array
+	if commandArgs, err = cli.parseOptions(); err != nil {
+		return
+	}
+
+	// do final checks
+	if err = cli.checkOptionValues(); err != nil {
+		return
+	}
 
 	// then parse collected arguments
-	if err == nil {
-		var n int
-		i = 0
-
-		// acquire arguments as required by the argSpecs
-		specIndex := -1
-		for index, argSpec := range cli.argSpecs {
-			specIndex = index
-			if n, err = argSpec.parse(cli, specIndex, args, i); err != nil {
-				break
-			}
-			i += n
-			if i >= len(args) {
-				break
-			}
-		}
-
-		// check if there are remaining arg-specs that require a value
-		if err == nil {
-			if i < len(args) {
-				err = fmt.Errorf("too many arguments: %d allowed", i)
-			} else {
-				specIndex++
-				if specIndex < len(cli.argSpecs) {
-					// skip all non required args
-					for _, spec := range cli.argSpecs[specIndex:] {
-						if !spec.getBase().required {
-							specIndex++
-						}
-					}
-				}
-				// return error if there are remaining arg-specs that require a value
-				if specIndex < len(cli.argSpecs) {
-					err = errTooFewArguments(len(cli.argSpecs))
-				}
-			}
-		}
-	}
+	err = cli.parseCommandArgs(commandArgs)
 	return
 }
 

opt-base.go

@@ -153,13 +153,13 @@ func (opt *cliOptionBase) fetchOptionValue(parser cliParser, argIndex int, value
 	return
 }
 
-func (opt *cliOptionBase) finalCheck(cliValue string) (err error) {
+func (opt *cliOptionBase) finalCheck() (err error) {
 	return
 }
 
-func (opt *cliOptionBase) checkValue(cliValue string, value any) (err error) {
+func (opt *cliOptionBase) checkValue(value any) (err error) {
 	if opt.finalCheckFunc != nil {
-		err = opt.finalCheckFunc(cliValue, value)
+		err = opt.finalCheckFunc(value)
 	}
 	return
 }

opt-bool.go

@@ -67,9 +67,9 @@ func (opt *cliOptionBool) parse(parser cliParser, argIndex int, valuePtr *string
 	return
 }
 
-func (opt *cliOptionBool) finalCheck(cliValue string) (err error) {
+func (opt *cliOptionBool) finalCheck() (err error) {
 	currentValue, _ := opt.getTargetVar()
-	return opt.getBase().checkValue(cliValue, currentValue)
+	return opt.getBase().checkValue(currentValue)
 }
 
 func (cli *CliParser) AddBoolOpt(name, short string, targetVar *bool, description string, aliases ...string) OptReference {

opt-int-array.go

@@ -75,7 +75,7 @@ func (opt *cliOptionIntArray) parse(parser cliParser, argIndex int, valuePtr *st
 						err = errInvalidOptionValue(opt.name, boxedValue, "num-array")
 					}
 				} else {
-					if !opt.alreadySeen {
+					if !opt.alreadySeen || (valuePtr != nil && parser.FlagIsSet(ResetOnEqualSign)) {
 						*opt.targetVar = []int{}
 						opt.alreadySeen = true
 					}
@@ -97,9 +97,9 @@ func (opt *cliOptionIntArray) parse(parser cliParser, argIndex int, valuePtr *st
 	return
 }
 
-func (opt *cliOptionIntArray) finalCheck(cliValue string) (err error) {
+func (opt *cliOptionIntArray) finalCheck() (err error) {
 	currentValue, _ := opt.getTargetVar()
-	return opt.getBase().checkValue(cliValue, currentValue)
+	return opt.getBase().checkValue(currentValue)
 }
 
 func (cli *CliParser) AddIntArrayOpt(name, short string, targetVar *[]int, defaultValue []int, description string, aliases ...string) OptReference {

opt-int.go

@@ -57,9 +57,9 @@ func (opt *cliOptionInt) parse(parser cliParser, argIndex int, valuePtr *string)
 	}
 	return
 }
-func (opt *cliOptionInt) finalCheck(cliValue string) (err error) {
+func (opt *cliOptionInt) finalCheck() (err error) {
 	currentValue, _ := opt.getTargetVar()
-	return opt.getBase().checkValue(cliValue, currentValue)
+	return opt.getBase().checkValue(currentValue)
 }
 
 func (cli *CliParser) AddIntOpt(name, short string, targetVar *int, defaultValue int, description string, aliases ...string) OptReference {

opt-multi.go

@@ -53,9 +53,9 @@ func (opt *cliOptionMulti) parse(parser cliParser, argIndex int, valuePtr *strin
 	value = "true"
 	return
 }
-func (opt *cliOptionMulti) finalCheck(cliValue string) (err error) {
+func (opt *cliOptionMulti) finalCheck() (err error) {
 	currentValue, _ := opt.getTargetVar()
-	return opt.getBase().checkValue(cliValue, currentValue)
+	return opt.getBase().checkValue(currentValue)
 }
 
 func (cli *CliParser) AddMultiOpt(name, short string, targetVar *int, defaultValue int, description string, aliases ...string) OptReference {

opt-string-array.go

@@ -85,7 +85,7 @@ func (cli *CliParser) AddStringArrayOpt(name, short string, targetVar *[]string,
 	return opt
 }
 
-func (opt *cliOptionStringArray) finalCheck(cliValue string) (err error) {
+func (opt *cliOptionStringArray) finalCheck() (err error) {
 	currentValue, _ := opt.getTargetVar()
-	return opt.getBase().checkValue(cliValue, currentValue)
+	return opt.getBase().checkValue(currentValue)
 }

opt-string-map.go

@@ -89,9 +89,9 @@ func (opt *cliOptionStringMap) parse(parser cliParser, argIndex int, valuePtr *s
 	return
 }
 
-func (opt *cliOptionStringMap) finalCheck(cliValue string) (err error) {
+func (opt *cliOptionStringMap) finalCheck() (err error) {
 	currentValue, _ := opt.getTargetVar()
-	return opt.getBase().checkValue(cliValue, currentValue)
+	return opt.getBase().checkValue(currentValue)
 }
 
 func (cli *CliParser) AddStringMapOpt(name, short string, targetVar *map[string]string, defaultValue map[string]string, description string, aliases ...string) OptReference {

opt-string.go

@@ -55,9 +55,9 @@ func (opt *cliOptionString) parse(parser cliParser, argIndex int, valuePtr *stri
 	}
 	return
 }
-func (opt *cliOptionString) finalCheck(cliValue string) (err error) {
+func (opt *cliOptionString) finalCheck() (err error) {
 	currentValue, _ := opt.getTargetVar()
-	return opt.getBase().checkValue(cliValue, currentValue)
+	return opt.getBase().checkValue(currentValue)
 }
 
 func (cli *CliParser) AddStringOpt(name, short string, targetVar *string, defaultValue string, description string, aliases ...string) OptReference {

opt_test.go

@@ -37,7 +37,7 @@ func TestOneOptWithEqual(t *testing.T) {
 func addBoxOption(cli *CliParser, boxPtr *[]int) {
 	// Define options
 	optRef := cli.AddIntArrayOpt("box", "b", boxPtr, []int{1, 2, 3, 4}, "Box spec: Left,Width,Top,Height; provide 4 int values")
-	optRef.OnFinalCheck(func(cliValue string, currentValue any) (err error) {
+	optRef.OnFinalCheck(func(currentValue any) (err error) {
 		if array, ok := currentValue.([]int); ok {
 			if len(array) != 4 {
 				err = fmt.Errorf("--box option requires exactly 4 items, %d provided", len(array))
@@ -49,8 +49,34 @@ func addBoxOption(cli *CliParser, boxPtr *[]int) {
 	})
 }
 
-func TestIntArrayOpt(t *testing.T) {
+func testIntArrayOptOk(t *testing.T, n int, args []string, flags ...int16) {
 	var box []int
+	var cli CliParser
+	t.Logf("Arg set n. %d", n)
+	addBoxOption(&cli, &box)
+	cli.Init(args, "1.0.0", "TestIntArrayOpt description", flags...)
+	if err := cli.Parse(); err != nil {
+		t.Error(err)
+	} else if len(box) != 4 {
+		t.Errorf(`Expected 4 items, got %d`, len(box))
+	}
+}
+
+func testIntArrayOptKo(t *testing.T, n int, args []string, msg string, flags ...int16) {
+	var box []int
+	var cli CliParser
+	t.Logf("Arg set n. %d", n)
+	addBoxOption(&cli, &box)
+	cli.Init(args, "1.0.0", "TestIntArrayOpt description", flags...)
+	if err := cli.Parse(); err == nil {
+		t.Errorf("Expected error, got nil")
+	} else if err.Error() != msg {
+		t.Errorf(`Invalid error: %q; expected: %q`, err.Error(), msg)
+	}
+}
+
+func TestIntArrayOpt(t *testing.T) {
+	var args []string
 	// Always recover from panic to return error before adding options
 	defer func() {
 		if r := recover(); r != nil {
@@ -61,68 +87,57 @@ func TestIntArrayOpt(t *testing.T) {
 		}
 	}()
 
-	args_1 := []string{
+	n := 0
+
+	n++
+	args = []string{
 		"TestIntArrayOpt",
 		"--box=100,200,150,450",
 	}
+	testIntArrayOptOk(t, n, args)
 
-	if true {
-		var cli CliParser
-		t.Logf("Arg set n. 1")
-		addBoxOption(&cli, &box)
-		cli.Init(args_1, "1.0.0", "TestIntArrayOpt description")
-		if err := cli.Parse(); err != nil {
-			t.Error(err)
-		} else if len(box) != 4 {
-			t.Errorf(`Expected 4 items, got %d`, len(box))
-		}
-	}
-
-	args_2 := []string{
+	n++
+	args = []string{
 		"TestIntArrayOpt",
 		"--box=100,200,150",
 	}
-	if true {
-		var cli CliParser
-		t.Logf("Arg set n. 2")
-		addBoxOption(&cli, &box)
-		cli.Init(args_2, "1.0.0", "TestIntArrayOpt description")
-		if err := cli.Parse(); err == nil {
-			t.Errorf("Expected error, got nil")
-		} else if err.Error() != "--box option requires exactly 4 items, 3 provided" {
-			t.Errorf(`Invalid error: %q; expected: "--box option requires exactly 4 items, 3 provided"`, err.Error())
-		}
-	}
+	testIntArrayOptKo(t, n, args, "--box option requires exactly 4 items, 3 provided")
 
-	args_3 := []string{
+	n++
+	args = []string{
 		"TestIntArrayOpt",
 		"--box", "100,200,150,450",
 	}
-	if true {
-		var cli CliParser
-		t.Logf("Arg set n. 3")
-		addBoxOption(&cli, &box)
-		cli.Init(args_3, "1.0.0", "TestIntArrayOpt description")
-		if err := cli.Parse(); err != nil {
-			t.Error(err)
-		} else if len(box) != 4 {
-			t.Errorf(`Expected 4 items, got %d`, len(box))
-		}
-	}
+	testIntArrayOptOk(t, n, args)
 
-	args_4 := []string{
+	n++
+	args = []string{
 		"TestIntArrayOpt",
 		"--box",
 	}
-	if true {
-		var cli CliParser
-		t.Logf("Arg set n. 4")
-		addBoxOption(&cli, &box)
-		cli.Init(args_4, "1.0.0", "TestIntArrayOpt description")
-		if err := cli.Parse(); err == nil {
-			t.Errorf("Expected error, got nil")
-		} else if err.Error() != `option "box" requires a value` {
-			t.Errorf(`Invalid error - Expected: 'option "box" requires a value'; got '%s'`, err.Error())
-		}
+	testIntArrayOptKo(t, n, args, `option "box" requires a value`)
+
+	n++
+	args = []string{
+		"TestIntArrayOpt",
+		"--box", "100,200,150",
+		"--box", "450",
 	}
+	testIntArrayOptOk(t, n, args)
+
+	n++
+	args = []string{
+		"TestIntArrayOpt",
+		"--box", "100,200,150",
+		"--box", "450,12",
+	}
+	testIntArrayOptKo(t, n, args, "--box option requires exactly 4 items, 5 provided")
+
+	n++
+	args = []string{
+		"TestIntArrayOpt",
+		"--box", "100,200,150",
+		"--box=100,200,150,450",
+	}
+	testIntArrayOptOk(t, n, args, ResetOnEqualSign)
 }

parser.go

@@ -104,16 +104,12 @@ func (cli *CliParser) parseArg(arg string, index int) (skipNextArg bool, err err
 	}
 	for i, optName := range opts {
 		if opt := cli.findOptionByArg(dashes + optName); opt != nil {
-			var optValue string
 			if equalPresent && i == len(opts)-1 {
-				_, optValue, err = opt.parse(cli, index, &value)
+				_, _, err = opt.parse(cli, index, &value)
 			} else if i < len(opts)-1 && opt.requiresValue() {
 				err = errMissingOptionValue(dashes + optName)
 			} else {
-				skipNextArg, optValue, err = opt.parse(cli, index, nil)
-			}
-			if err == nil && i == len(opts)-1 {
-				err = opt.finalCheck(optValue)
+				skipNextArg, _, err = opt.parse(cli, index, nil)
 			}
 		} else {
 			err = errUnknownOption(dashes + optName)