From b0d37d1fb2b491a861f788a41aabbe66cbf83110 Mon Sep 17 00:00:00 2001
From: Fredrik Wallgren <fredrik.wallgren@gmail.com>
Date: Thu, 19 Nov 2015 14:34:09 +0100
Subject: [PATCH] Add default values to usage
Check if the value isn't it's zero value and if not add a default value
to the usage text.
---
usage.go | 8 +++++++-
usage_test.go | 10 ++++++++--
2 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/usage.go b/usage.go
index 9404015..64ed901 100644
--- a/usage.go
+++ b/usage.go
@@ -76,7 +76,6 @@ func (p *Parser) WriteHelp(w io.Writer) {
}
}
- // write the list of options
fmt.Fprint(w, "\noptions:\n")
for _, spec := range options {
printOption(w, spec)
@@ -101,6 +100,13 @@ func printOption(w io.Writer, spec *spec) {
}
fmt.Fprint(w, spec.help)
}
+ // Check if spec.dest is zero value or not
+ // If it isn't a default value have been added
+ v := spec.dest
+ z := reflect.Zero(v.Type())
+ if v.Interface() != z.Interface() {
+ fmt.Fprintf(w, " [default: %v]", v)
+ }
fmt.Fprint(w, "\n")
}
diff --git a/usage_test.go b/usage_test.go
index 5a9199c..01c9542 100644
--- a/usage_test.go
+++ b/usage_test.go
@@ -10,15 +10,17 @@ import (
)
func TestWriteUsage(t *testing.T) {
- expectedUsage := "usage: example [--verbose] [--dataset DATASET] [--optimize OPTIMIZE] INPUT [OUTPUT [OUTPUT ...]]\n"
+ expectedUsage := "usage: example [--name NAME] [--value VALUE] [--verbose] [--dataset DATASET] [--optimize OPTIMIZE] INPUT [OUTPUT [OUTPUT ...]]\n"
- expectedHelp := `usage: example [--verbose] [--dataset DATASET] [--optimize OPTIMIZE] INPUT [OUTPUT [OUTPUT ...]]
+ expectedHelp := `usage: example [--name NAME] [--value VALUE] [--verbose] [--dataset DATASET] [--optimize OPTIMIZE] INPUT [OUTPUT [OUTPUT ...]]
positional arguments:
input
output
options:
+ --name NAME name to use [default: Foo Bar]
+ --value VALUE secret value [default: 42]
--verbose, -v verbosity level
--dataset DATASET dataset to use
--optimize OPTIMIZE, -O OPTIMIZE
@@ -28,10 +30,14 @@ options:
var args struct {
Input string `arg:"positional"`
Output []string `arg:"positional"`
+ Name string `arg:"help:name to use"`
+ Value int `arg:"help:secret value"`
Verbose bool `arg:"-v,help:verbosity level"`
Dataset string `arg:"help:dataset to use"`
Optimize int `arg:"-O,help:optimization level"`
}
+ args.Name = "Foo Bar"
+ args.Value = 42
p, err := NewParser(&args)
require.NoError(t, err)