Merge pull request #431 from LeGEC/430-fix-usage-message-for-func-flags

fix usage message for func flags, fix arguments order

1 files changed, 32 insertions, 2 deletions

diff --git a/bool_func_test.go b/bool_func_test.go
index c81970a..c16be83 100644
--- a/bool_func_test.go
+++ b/bool_func_test.go
@@ -75,7 +75,7 @@ func TestBoolFuncCompat(t *testing.T) {
 		args := []string{"--bflag", "--bflag=false", "--bflag=1", "--bflag=bar", "--bflag="}
 
 		// It turns out that, even though the function is called "BoolFunc",
-		// the stanard flag package does not try to parse the value assigned to
+		// the standard flag package does not try to parse the value assigned to
 		// that cli flag as a boolean. The string provided on the command line is
 		// passed as is to the callback.
 		//   e.g: with "--bflag=not_a_bool" on the command line, the FlagSet does not
@@ -106,7 +106,7 @@ func TestBoolFuncCompat(t *testing.T) {
 		flagName := "bflag"
 		args := []string{"--bflag", "--bflag=err", "--bflag=after"}
 
-		// test behavior of standard flag.Fset with an error triggere by the callback:
+		// test behavior of standard flag.Fset with an error triggered by the callback:
 		// (note: as can be seen in 'runCase()', if the callback sees "err" as a value
 		//  for the bool flag, it will return an error)
 		stdFSet := flag.NewFlagSet("std test", flag.ContinueOnError)
@@ -145,3 +145,33 @@ func TestBoolFuncCompat(t *testing.T) {
 		}
 	})
 }
+
+func TestBoolFuncUsage(t *testing.T) {
+	t.Run("regular func flag", func(t *testing.T) {
+		// regular boolfunc flag:
+		// expect to see '--flag1' followed by the usageMessage, and no mention of a default value
+		fset := NewFlagSet("unittest", ContinueOnError)
+		fset.BoolFunc("flag1", "usage message", func(s string) error { return nil })
+		usage := fset.FlagUsagesWrapped(80)
+
+		usage = strings.TrimSpace(usage)
+		expected := "--flag1   usage message"
+		if usage != expected {
+			t.Fatalf("unexpected generated usage message\n  expected: %s\n       got: %s", expected, usage)
+		}
+	})
+
+	t.Run("func flag with placeholder name", func(t *testing.T) {
+		// func flag, with a placeholder name:
+		// if usageMesage contains a placeholder, expect '--flag2 {placeholder}'; still expect no mention of a default value
+		fset := NewFlagSet("unittest", ContinueOnError)
+		fset.BoolFunc("flag2", "usage message with `name` placeholder", func(s string) error { return nil })
+		usage := fset.FlagUsagesWrapped(80)
+
+		usage = strings.TrimSpace(usage)
+		expected := "--flag2 name   usage message with name placeholder"
+		if usage != expected {
+			t.Fatalf("unexpected generated usage message\n  expected: %s\n       got: %s", expected, usage)
+		}
+	})
+}