fix some cli parsing bugs and add unit test coverage (#2)

pkg/cli/cli.go

@@ -44,50 +44,91 @@ func New(binaryName string, shortUsage string, longUsage, examples string) Comma
 	}
 }
 
-// ParseAndValidateFlags will parse flags registered in this instance of CLI from os.Args
-// and then perform validation
-func (cl *CommandLineInterface) ParseAndValidateFlags() (map[string]interface{}, error) {
+// ParseFlags will parse flags registered in this instance of CLI from os.Args
+func (cl *CommandLineInterface) ParseFlags() (map[string]interface{}, error) {
 	cl.setUsageTemplate()
 	// Remove Suite Flags so that args only include Config and Filter Flags
-	cl.rootCmd.SetArgs(cl.removeIntersectingArgs(cl.suiteFlags))
+	cl.rootCmd.SetArgs(removeIntersectingArgs(cl.suiteFlags))
 	// This parses Config and Filter flags only
 	err := cl.rootCmd.Execute()
 	if err != nil {
 		return nil, err
 	}
 	// Remove Config and Filter flags so that only suite flags are parsed
-	err = cl.suiteFlags.Parse(cl.removeIntersectingArgs(cl.rootCmd.Flags()))
+	err = cl.suiteFlags.Parse(removeIntersectingArgs(cl.rootCmd.Flags()))
 	if err != nil {
 		return nil, err
 	}
 	// Add suite flags to rootCmd flagset so that other processing can occur
 	// This has to be done after usage is printed so that the flagsets can be grouped properly when printed
 	cl.rootCmd.Flags().AddFlagSet(cl.suiteFlags)
-	err = cl.SetUntouchedFlagValuesToNil()
+	err = cl.setUntouchedFlagValuesToNil()
 	if err != nil {
 		return nil, err
 	}
-	err = cl.ProcessRangeFilterFlags()
+	err = cl.processRangeFilterFlags()
+	if err != nil {
+		return nil, err
+	}
+	return cl.Flags, nil
+}
+
+// ParseAndValidateFlags will parse flags registered in this instance of CLI from os.Args
+// and then perform validation
+func (cl *CommandLineInterface) ParseAndValidateFlags() (map[string]interface{}, error) {
+	flags, err := cl.ParseFlags()
 	if err != nil {
 		return nil, err
 	}
 	err = cl.ValidateFlags()
 	if err != nil {
 		return nil, err
 	}
-	return cl.Flags, nil
+	return flags, nil
 }
 
-func (cl *CommandLineInterface) removeIntersectingArgs(flagSet *pflag.FlagSet) []string {
-	newArgs := os.Args[1:]
-	for i, arg := range newArgs {
-		if flagSet.Lookup(strings.Replace(arg, "--", "", 1)) != nil || (len(arg) == 2 && flagSet.ShorthandLookup(strings.Replace(arg, "-", "", 1)) != nil) {
-			newArgs = append(newArgs[:i], newArgs[i+1:]...)
+// ValidateFlags iterates through any registered validators and executes them
+func (cl *CommandLineInterface) ValidateFlags() error {
+	for flagName, validationFn := range cl.validators {
+		if validationFn == nil {
+			continue
+		}
+		err := validationFn(cl.Flags[flagName])
+		if err != nil {
+			return err
 		}
 	}
+	return nil
+}
+
+func removeIntersectingArgs(flagSet *pflag.FlagSet) []string {
+	newArgs := []string{}
+	skipNext := false
+	for i, arg := range os.Args {
+		if skipNext {
+			skipNext = false
+			continue
+		}
+		arg = strings.Split(arg, "=")[0]
+		longFlag := strings.Replace(arg, "--", "", 1)
+		if flagSet.Lookup(longFlag) != nil || shorthandLookup(flagSet, arg) != nil {
+			if len(os.Args) > i+1 && os.Args[i+1][0] != '-' {
+				skipNext = true
+			}
+			continue
+		}
+		newArgs = append(newArgs, os.Args[i])
+	}
 	return newArgs
 }
 
+func shorthandLookup(flagSet *pflag.FlagSet, arg string) *pflag.Flag {
+	if len(arg) == 2 && arg[0] == '-' && arg[1] != '-' {
+		return flagSet.ShorthandLookup(strings.Replace(arg, "-", "", 1))
+	}
+	return nil
+}
+
 func (cl *CommandLineInterface) setUsageTemplate() {
 	transformedUsage := usageTemplate
 	suiteFlagCount := 0
@@ -104,9 +145,9 @@ func (cl *CommandLineInterface) setUsageTemplate() {
 	cl.rootCmd.Flags().Usage = func() {}
 }
 
-// SetUntouchedFlagValuesToNil iterates through all flags and sets their value to nil if they were not specifically set by the user
+// setUntouchedFlagValuesToNil iterates through all flags and sets their value to nil if they were not specifically set by the user
 // This allows for a specified value, a negative value (like false or empty string), or an unspecified (nil) entry.
-func (cl *CommandLineInterface) SetUntouchedFlagValuesToNil() error {
+func (cl *CommandLineInterface) setUntouchedFlagValuesToNil() error {
 	defaultHandlerErrMsg := "Unable to find a default value handler for %v, marking as no default value. This could be an error"
 	defaultHandlerFlags := []string{}
 
@@ -141,8 +182,8 @@ func (cl *CommandLineInterface) SetUntouchedFlagValuesToNil() error {
 	return nil
 }
 
-// ProcessRangeFilterFlags sets min and max to the appropriate 0 or maxInt bounds based on the 3-tuple that a user specifies for base flag, min, and/or max
-func (cl *CommandLineInterface) ProcessRangeFilterFlags() error {
+// processRangeFilterFlags sets min and max to the appropriate 0 or maxInt bounds based on the 3-tuple that a user specifies for base flag, min, and/or max
+func (cl *CommandLineInterface) processRangeFilterFlags() error {
 	for flagName := range cl.intRangeFlags {
 		rangeHelperMin := fmt.Sprintf("%s-%s", flagName, "min")
 		rangeHelperMax := fmt.Sprintf("%s-%s", flagName, "max")
@@ -167,17 +208,3 @@ func (cl *CommandLineInterface) ProcessRangeFilterFlags() error {
 	}
 	return nil
 }
-
-// ValidateFlags iterates through any registered validators and executes them
-func (cl *CommandLineInterface) ValidateFlags() error {
-	for flagName, validationFn := range cl.validators {
-		if validationFn == nil {
-			continue
-		}
-		err := validationFn(cl.Flags[flagName])
-		if err != nil {
-			return err
-		}
-	}
-	return nil
-}

pkg/cli/cli_internal_test.go

@@ -0,0 +1,48 @@
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//     http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
+package cli
+
+import (
+	"os"
+	"testing"
+
+	h "github.com/aws/amazon-ec2-instance-selector/pkg/test"
+	"github.com/spf13/pflag"
+)
+
+// Tests
+
+func TestRemoveIntersectingArgs(t *testing.T) {
+	flagSet := pflag.NewFlagSet("test-flag-set", pflag.ContinueOnError)
+	flagSet.Bool("test-bool", false, "test usage")
+	os.Args = []string{"ec2-instance-selector", "--test-bool", "--this-should-stay"}
+	newArgs := removeIntersectingArgs(flagSet)
+	h.Assert(t, len(newArgs) == 2, "NewArgs should only include the bin name and one argument after removing intersections")
+}
+
+func TestRemoveIntersectingArgs_NextArg(t *testing.T) {
+	flagSet := pflag.NewFlagSet("test-flag-set", pflag.ContinueOnError)
+	flagSet.String("test-str", "", "test usage")
+	os.Args = []string{"ec2-instance-selector", "--test-str", "somevalue", "--this-should-stay", "valuetostay"}
+	newArgs := removeIntersectingArgs(flagSet)
+	h.Assert(t, len(newArgs) == 3, "NewArgs should only include the bin name and a flag + input after removing intersections")
+}
+
+func TestRemoveIntersectingArgs_ShorthandArg(t *testing.T) {
+	flagSet := pflag.NewFlagSet("test-flag-set", pflag.ContinueOnError)
+	flagSet.StringP("test-str", "t", "", "test usage")
+	os.Args = []string{"ec2-instance-selector", "--test-str", "somevalue", "--this-should-stay", "valuetostay", "-t", "test"}
+	newArgs := removeIntersectingArgs(flagSet)
+	h.Assert(t, len(newArgs) == 3, "NewArgs should only include the bin name and a flag + input after removing intersections")
+}