diff options
| -rw-r--r-- | README.md | 27 | ||||
| -rw-r--r-- | flag.go | 21 | ||||
| -rw-r--r-- | golangflag.go | 22 | ||||
| -rw-r--r-- | golangflag_test.go | 16 |
4 files changed, 81 insertions, 5 deletions
@@ -284,6 +284,33 @@ func main() { } ``` +### Using pflag with go test +`pflag` does not parse the shorthand versions of go test's built-in flags (i.e., those starting with `-test.`). +For more context, see issues [#63](https://github.com/spf13/pflag/issues/63) and [#238](https://github.com/spf13/pflag/issues/238) for more details. + +For example, if you use pflag in your `TestMain` function and call `pflag.Parse()` after defining your custom flags, running a test like this: +```bash +go test /your/tests -run ^YourTest -v --your-test-pflags +``` +will result in the `-v` flag being ignored. This happens because of the way pflag handles flag parsing, skipping over go test's built-in shorthand flags. +To work around this, you can use the `ParseSkippedFlags` function, which ensures that go test's flags are parsed separately using the standard flag package. + +**Example**: You want to parse go test flags that are otherwise ignore by `pflag.Parse()` +```go +import ( + goflag "flag" + flag "github.com/spf13/pflag" +) + +var ip *int = flag.Int("flagname", 1234, "help message for flagname") + +func main() { + flag.CommandLine.AddGoFlagSet(goflag.CommandLine) + flag.ParseSkippedFlags(os.Args[1:], goflag.CommandLine) + flag.Parse() +} +``` + ## More info You can see the full reference documentation of the pflag package @@ -27,23 +27,32 @@ unaffected. Define flags using flag.String(), Bool(), Int(), etc. This declares an integer flag, -flagname, stored in the pointer ip, with type *int. + var ip = flag.Int("flagname", 1234, "help message for flagname") + If you like, you can bind the flag to a variable using the Var() functions. + var flagvar int func init() { flag.IntVar(&flagvar, "flagname", 1234, "help message for flagname") } + Or you can create custom flags that satisfy the Value interface (with pointer receivers) and couple them to flag parsing by + flag.Var(&flagVal, "name", "help message for flagname") + For such flags, the default value is just the initial value of the variable. After all flags are defined, call + flag.Parse() + to parse the command line into the defined flags. Flags may then be used directly. If you're using the flags themselves, they are all pointers; if you bind to variables, they're values. + fmt.Println("ip has value ", *ip) fmt.Println("flagvar has value ", flagvar) @@ -54,22 +63,26 @@ The arguments are indexed from 0 through flag.NArg()-1. The pflag package also defines some new functions that are not in flag, that give one-letter shorthands for flags. You can use these by appending 'P' to the name of any function that defines a flag. + var ip = flag.IntP("flagname", "f", 1234, "help message") var flagvar bool func init() { flag.BoolVarP(&flagvar, "boolname", "b", true, "help message") } flag.VarP(&flagval, "varname", "v", "help message") + Shorthand letters can be used with single dashes on the command line. Boolean shorthand flags can be combined with other shorthand flags. Command line flag syntax: + --flag // boolean flags only --flag=x Unlike the flag package, a single dash before an option means something different than a double dash. Single dashes signify a series of shorthand letters for flags. All but the last shorthand letter must be boolean flags. + // boolean flags -f -abc @@ -934,9 +947,9 @@ func (f *FlagSet) usage() { } } -//--unknown (args will be empty) -//--unknown --next-flag ... (args will be --next-flag ...) -//--unknown arg ... (args will be arg ...) +// --unknown (args will be empty) +// --unknown --next-flag ... (args will be --next-flag ...) +// --unknown arg ... (args will be arg ...) func stripUnknownFlagValue(args []string) []string { if len(args) == 0 { //--unknown @@ -1014,7 +1027,7 @@ func (f *FlagSet) parseLongArg(s string, args []string, fn parseFunc) (a []strin func (f *FlagSet) parseSingleShortArg(shorthands string, args []string, fn parseFunc) (outShorts string, outArgs []string, err error) { outArgs = args - if strings.HasPrefix(shorthands, "test.") { + if isGotestShorthandFlag(shorthands) { return } diff --git a/golangflag.go b/golangflag.go index d3dd72b..f563907 100644 --- a/golangflag.go +++ b/golangflag.go @@ -10,6 +10,15 @@ import ( "strings" ) +// go test flags prefixes +func isGotestFlag(flag string) bool { + return strings.HasPrefix(flag, "-test.") +} + +func isGotestShorthandFlag(flag string) bool { + return strings.HasPrefix(flag, "test.") +} + // flagValueWrapper implements pflag.Value around a flag.Value. The main // difference here is the addition of the Type method that returns a string // name of the type. As this is generally unknown, we approximate that with @@ -103,3 +112,16 @@ func (f *FlagSet) AddGoFlagSet(newSet *goflag.FlagSet) { } f.addedGoFlagSets = append(f.addedGoFlagSets, newSet) } + +// ParseSkippedFlags explicitly Parses go test flags (i.e. the one starting with '-test.') with goflag.Parse(), +// since by default those are skipped by pflag.Parse(). +// Typical usage example: `ParseGoTestFlags(os.Args[1:], goflag.CommandLine)` +func ParseSkippedFlags(osArgs []string, goFlagSet *goflag.FlagSet) error { + var skippedFlags []string + for _, f := range osArgs { + if isGotestFlag(f) { + skippedFlags = append(skippedFlags, f) + } + } + return goFlagSet.Parse(skippedFlags) +} diff --git a/golangflag_test.go b/golangflag_test.go index 5bd831b..2ecefef 100644 --- a/golangflag_test.go +++ b/golangflag_test.go @@ -12,11 +12,14 @@ import ( func TestGoflags(t *testing.T) { goflag.String("stringFlag", "stringFlag", "stringFlag") goflag.Bool("boolFlag", false, "boolFlag") + var testxxxValue string + goflag.StringVar(&testxxxValue, "test.xxx", "test.xxx", "it is a test flag") f := NewFlagSet("test", ContinueOnError) f.AddGoFlagSet(goflag.CommandLine) - err := f.Parse([]string{"--stringFlag=bob", "--boolFlag"}) + args := []string{"--stringFlag=bob", "--boolFlag", "-test.xxx=testvalue"} + err := f.Parse(args) if err != nil { t.Fatal("expected no error; get", err) } @@ -40,6 +43,17 @@ func TestGoflags(t *testing.T) { t.Fatal("f.Parsed() return false after f.Parse() called") } + if testxxxValue != "test.xxx" { + t.Fatalf("expected testxxxValue to be test.xxx but got %v", testxxxValue) + } + err = ParseSkippedFlags(args, goflag.CommandLine) + if err != nil { + t.Fatal("expected no error; ParseSkippedFlags", err) + } + if testxxxValue != "testvalue" { + t.Fatalf("expected testxxxValue to be testvalue but got %v", testxxxValue) + } + // in fact it is useless. because `go test` called flag.Parse() if !goflag.CommandLine.Parsed() { t.Fatal("goflag.CommandLine.Parsed() return false after f.Parse() called") |