Allow extra flags in the config file

README.md

@@ -13,7 +13,7 @@ $ cat > gopher.go
 
     import (
         "fmt"
-    	"github.com/namsral/flag"
+    	"github.com/robert-zaremba/flag"
 	)
 
     func main() {
@@ -83,7 +83,7 @@ It's intended for projects which require a simple configuration made available t
 Example:
 
 ```go
-import "github.com/namsral/flag"
+import "github.com/robert-zaremba/flag"
 
 flag.String(flag.DefaultConfigFlagname, "", "path to config file")
 flag.Int("age", 24, "help message for age")
@@ -161,7 +161,7 @@ age=33
 
 For more examples see the [examples][] directory in the project repository.
 
-[examples]: https://github.com/namsral/flag/tree/master/examples
+[examples]: https://github.com/robert-zaremba/flag/tree/master/examples
 
 That's it.
 

examples/gopher.go

@@ -1,7 +1,7 @@
 package main
 
 import (
-    "github.com/namsral/flag"
+    "github.com/robert-zaremba/flag"
     "fmt"
     )
 

extras.go

@@ -152,7 +152,8 @@ func (f *FlagSet) ParseFile(path string) error {
 				f.usage()
 				return ErrHelp
 			}
-			return f.failf("configuration variable provided but not defined: %s", name)
+			// ignore if extra flag is defined in the config file
+			continue
 		}
 
 		if fv, ok := flag.Value.(boolFlag); ok && fv.IsBoolFlag() { // special case: doesn't need an arg
@@ -177,9 +178,5 @@ func (f *FlagSet) ParseFile(path string) error {
 		f.actual[name] = flag
 	}
 
-	if err := scanner.Err(); err != nil {
-		return err
-	}
-
-	return nil
+	return scanner.Err()
 }

extras_test.go

@@ -10,9 +10,17 @@ import (
 	"testing"
 	"time"
 
-	. "github.com/namsral/flag"
+	. "github.com/robert-zaremba/flag"
 )
 
+// ResetForTesting clears all flag state and sets the usage function as directed.
+// After calling ResetForTesting, parse errors in flag handling will not
+// exit the program.
+func ResetForTesting(usage func()) {
+	CommandLine = NewFlagSet(os.Args[0], ContinueOnError)
+	Usage = usage
+}
+
 // Test parsing a environment variables
 func TestParseEnv(t *testing.T) {
 

flag.go

@@ -871,7 +871,7 @@ func (f *FlagSet) parseOne() (bool, error) {
 		}
 	}
 	m := f.formal
-	flag, alreadythere := m[name] // BUG
+	flag, alreadythere := m[name]
 	if !alreadythere {
 		if name == "help" || name == "h" { // special case for nice help message.
 			f.usage()

flag_test.go

@@ -13,7 +13,7 @@ import (
 	"testing"
 	"time"
 
-	. "github.com/namsral/flag"
+	. "github.com/robert-zaremba/flag"
 )
 
 func boolString(s string) string {
@@ -379,6 +379,16 @@ func TestHelp(t *testing.T) {
 	}
 }
 
+const defaultOutput2 = "  -A=false: for bootstrapping, allow 'any' type\n" +
+	"  -Alongflagname=false: disable bounds checking\n" +
+	"  -C=true: a boolean defaulting to true\n" +
+	"  -D=\"\": set relative `path` for local imports\n" +
+	"  -F=2.7: a non-zero `number`\n" +
+	"  -G=0: a float that defaults to zero\n" +
+	"  -N=27: a non-zero int\n" +
+	"  -Z=0: an int that defaults to zero\n" +
+	"  -maxT=0s: set `timeout` for dial\n"
+
 const defaultOutput = `  -A	for bootstrapping, allow 'any' type
   -Alongflagname
     	disable bounds checking
@@ -413,6 +423,6 @@ func TestPrintDefaults(t *testing.T) {
 	fs.PrintDefaults()
 	got := buf.String()
 	if got != defaultOutput {
-		t.Errorf("got %q want %q\n", got, defaultOutput)
+		t.Errorf("got\n%q want\n%q\n", got, defaultOutput)
 	}
 }

go.mod

@@ -0,0 +1,10 @@
+module github.com/robert-zaremba/flag
+
+go 1.13
+
+require (
+	github.com/robert-zaremba/checkers v1.0.1
+	github.com/robert-zaremba/errstack v1.0.2
+	github.com/robert-zaremba/go-bat v1.0.1
+	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f
+)

go.sum

@@ -0,0 +1,29 @@
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/facebookgo/stack v0.0.0-20160209184415-751773369052 h1:JWuenKqqX8nojtoVVWjGfOF9635RETekkoH6Cc9SX0A=
+github.com/facebookgo/stack v0.0.0-20160209184415-751773369052/go.mod h1:UbMTZqLaRiH3MsBH8va0n7s1pQYcu3uTb8G4tygF4Zg=
+github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0 h1:iQTw/8FWTuc7uiaSepXwyf3o52HaUYcV+Tu66S3F5GA=
+github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0/go.mod h1:1NbS8ALrpOvjt0rHPNLyCIeMtbizbir8U//inJ+zuB8=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/mozillazg/go-unidecode v0.1.1 h1:uiRy1s4TUqLbcROUrnCN/V85Jlli2AmDF6EeAXOeMHE=
+github.com/mozillazg/go-unidecode v0.1.1/go.mod h1:fYMdhyjni9ZeEmS6OE/GJHDLsF8TQvIVDwYR/drR26Q=
+github.com/namsral/flag v1.7.4-pre h1:b2ScHhoCUkbsq0d2C15Mv+VU8bl8hAXV8arnWiOHNZs=
+github.com/namsral/flag v1.7.4-pre/go.mod h1:OXldTctbM6SWH1K899kPZcf65KxJiD7MsceFUpB5yDo=
+github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
+github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
+github.com/robert-zaremba/checkers v1.0.1 h1:AjxF5P+YkOeWsvFSbTcdk/0lvNDDdkzaM3HrEc4XSEE=
+github.com/robert-zaremba/checkers v1.0.1/go.mod h1:wUVuqhZje9IKym5bZuW1nbA0GqRRgnYTMehly17F56Q=
+github.com/robert-zaremba/errstack v1.0.2 h1:WSNVsQnd3YFLDBW1FysLkJxHkbRsbpgaYk7R8gBJyRQ=
+github.com/robert-zaremba/errstack v1.0.2/go.mod h1:KCGDqMDzP5xgeKXM33WryQ8+Zj7EaxnP+J6t3OBhU14=
+github.com/robert-zaremba/errstack v3.1.0+incompatible h1:wLAs0u9qr7u4s9UVtCAhx1I4dagUVx5d/MuYhK9sNr4=
+github.com/robert-zaremba/errstack v3.1.0+incompatible/go.mod h1:YiMUuTTLstXOe9Ao1J0w0eTf8CaGS+q4WDIJaypSwVI=
+github.com/robert-zaremba/go-bat v1.0.1 h1:5C/UryVjj0sKPvT4UPCI2gaIrsXR7sXASMM45ZxCcKo=
+github.com/robert-zaremba/go-bat v1.0.1/go.mod h1:GYLn+EyFubUfo/yPrQsma+cri4vCjRC+Qlovomu6sWw=
+github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=
+github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
+gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
+gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

setup.go

@@ -0,0 +1,30 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package flag
+
+import (
+	"fmt"
+	"os"
+)
+
+// Setup parses flag and setups usage function.
+// `positionalArgs` is a string representing positional args, eg: "arg1 arg2 arg3"
+// `commands` if provided is a positional argument command description.
+func Setup(version, positionalArgs string, commands ...string) {
+	Usage = func() {
+		fmt.Fprintln(os.Stderr, "Version: ", version)
+		if len(commands) != 0 {
+			fmt.Fprintf(os.Stderr,
+				"USAGE: %s <commands> <parameters> %s\n\n", os.Args[0], positionalArgs)
+			fmt.Fprint(os.Stderr, "COMMANDS:", commands[0], "\n\n")
+		} else {
+			fmt.Fprintf(os.Stderr,
+				"USAGE: %s <parameters> %s\n\n", os.Args[0], positionalArgs)
+		}
+		fmt.Fprintln(os.Stderr, "PARAMETERS:")
+		PrintDefaults()
+	}
+	Parse()
+}

srv.go

@@ -0,0 +1,73 @@
+package flag
+
+import (
+	"flag"
+	"net/url"
+	"os"
+
+	"github.com/robert-zaremba/errstack"
+	bat "github.com/robert-zaremba/go-bat"
+)
+
+// URL is a structure containing network connection details to a service
+// The value should have the following structure:
+//     //username:password@host:port/directory
+type URL struct {
+	url.URL
+}
+
+// Set implements github.com/robert-zaremba/flag Value interface
+func (a *URL) Set(value string) error {
+	u, err := url.Parse(value)
+	if err != nil {
+		return errstack.WrapAsReq(err, "Can't parse network address config")
+	}
+	a.URL = *u
+	return nil
+}
+
+// Path represents a file in a filesystem
+type Path struct {
+	Path string
+}
+
+// Set implements github.com/robert-zaremba/flag Value interface
+func (a *Path) Set(filePath string) error {
+	a.Path = filePath
+	return a.Check()
+}
+
+// String implements github.com/robert-zaremba/flag Value interface
+func (a *Path) String() string {
+	return a.Path
+}
+
+// Check returns an error if it can't find the file
+func (a Path) Check() error {
+	if a.Path == "" {
+		return errstack.NewReq("File path can't be empty")
+	}
+	_, err := os.Stat(a.Path)
+	return err
+}
+
+// SrvFlags represents common server flags
+type SrvFlags struct {
+	Production *bool
+	Port       *string
+}
+
+// NewSrvFlags setups common server flags
+func NewSrvFlags() SrvFlags {
+	return SrvFlags{
+		flag.Bool("production", false, "Run in production mode"),
+		flag.String("port", "8000", "The HTTP listening port"),
+	}
+}
+
+// Check validates the flags. It may panic!
+func (f SrvFlags) Check() error {
+	errb := errstack.NewBuilder()
+	bat.Atoi64Errp(*f.Port, errb.Putter("port"))
+	return errb.ToReqErr()
+}

srv_test.go

@@ -0,0 +1,54 @@
+package flag
+
+import (
+	"testing"
+
+	rzcheck "github.com/robert-zaremba/checkers"
+	gocheck "gopkg.in/check.v1"
+)
+
+// Hook up gocheck into the "go test" runner.
+func Test(t *testing.T) { gocheck.TestingT(t) }
+
+type ExtraSuite struct{}
+
+func init() {
+	gocheck.Suite(&ExtraSuite{})
+}
+
+func (s *ExtraSuite) TestValidateDirExists(c *gocheck.C) {
+	ff := Path{}
+	err := ff.Set("/tmp")
+	c.Assert(err, gocheck.IsNil)
+	c.Assert(ff.String(), gocheck.Equals, "/tmp")
+}
+
+func (s *ExtraSuite) TestValidatePermissionDenied(c *gocheck.C) {
+	ff := Path{}
+	_ = ff.Set("/root/secret")
+	err := ff.Check()
+	c.Assert(err, gocheck.ErrorMatches, "stat /root/secret: permission denied")
+}
+
+func (s *ExtraSuite) TestValidateNoFile(c *gocheck.C) {
+	ff := Path{}
+	_ = ff.Set("")
+	err := ff.Check()
+	c.Assert(err, rzcheck.ErrorContains, "File path can't be empty")
+}
+
+func (s *ExtraSuite) TestHandleBadDefaultWithPanic(c *gocheck.C) {
+	ff := Path{"hello-world"}
+	err := ff.Check()
+	c.Assert(err, gocheck.ErrorMatches, "stat hello-world: no such file or directory")
+}
+
+func (s *ExtraSuite) TestHandleDefault(c *gocheck.C) {
+	ff := Path{"/tmp"}
+	c.Assert(ff.String(), gocheck.Equals, "/tmp")
+	ff = Path{"/"}
+	c.Assert(ff.String(), gocheck.Equals, "/")
+	err := ff.Set("/tmp")
+	c.Assert(err, gocheck.IsNil)
+	c.Assert(ff.String(), gocheck.Equals, "/tmp")
+}

validate.go

@@ -0,0 +1,37 @@
+package flag
+
+import (
+	"flag"
+	"fmt"
+	"strings"
+)
+
+// Checker is an interface for type which has a Check function
+type Checker interface {
+	Check() error
+}
+
+// Validate runs flag checkers
+func Validate(positionalArgs string, checkers ...Checker) error {
+	expected := strings.Fields(positionalArgs)
+	if len(expected) != flag.NArg() {
+		return fmt.Errorf("missing required positional arguments: %s. Number of args Provided: %d, expected: %d",
+			expected, flag.NArg(), len(expected))
+	}
+	for _, c := range checkers {
+		if err := c.Check(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// CheckMany is a helper function to check many flag components
+func CheckMany(checkers ...Checker) error {
+	for _, c := range checkers {
+		if err := c.Check(); err != nil {
+			return err
+		}
+	}
+	return nil
+}