Merge pull request #116 from denysvitali/master

feat(usage): Include env variable in usage

2 files changed, 26 insertions, 9 deletions

diff --git a/usage.go b/usage.go
index db43dd1..a741570 100644
--- a/usage.go
+++ b/usage.go
@@ -101,7 +101,7 @@ func (p *Parser) writeUsageForCommand(w io.Writer, cmd *command) {
 	fmt.Fprint(w, "\n")
 }
 
-func printTwoCols(w io.Writer, left, help string, defaultVal string) {
+func printTwoCols(w io.Writer, left, help string, defaultVal string, envVal string) {
 	lhs := "  " + left
 	fmt.Fprint(w, lhs)
 	if help != "" {
@@ -112,8 +112,23 @@ func printTwoCols(w io.Writer, left, help string, defaultVal string) {
 		}
 		fmt.Fprint(w, help)
 	}
+
+	bracketsContent := []string{}
+
 	if defaultVal != "" {
-		fmt.Fprintf(w, " [default: %s]", defaultVal)
+		bracketsContent = append(bracketsContent,
+			fmt.Sprintf("default: %s", defaultVal),
+		)
+	}
+
+	if envVal != "" {
+		bracketsContent = append(bracketsContent,
+			fmt.Sprintf("env: %s", envVal),
+		)
+	}
+
+	if len(bracketsContent) > 0 {
+		fmt.Fprintf(w, " [%s]", strings.Join(bracketsContent, ", "))
 	}
 	fmt.Fprint(w, "\n")
 }
@@ -147,7 +162,7 @@ func (p *Parser) writeHelpForCommand(w io.Writer, cmd *command) {
 	if len(positionals) > 0 {
 		fmt.Fprint(w, "\nPositional arguments:\n")
 		for _, spec := range positionals {
-			printTwoCols(w, spec.placeholder, spec.help, "")
+			printTwoCols(w, spec.placeholder, spec.help, "", "")
 		}
 	}
 
@@ -194,7 +209,7 @@ func (p *Parser) writeHelpForCommand(w io.Writer, cmd *command) {
 	if len(cmd.subcommands) > 0 {
 		fmt.Fprint(w, "\nCommands:\n")
 		for _, subcmd := range cmd.subcommands {
-			printTwoCols(w, subcmd.name, subcmd.help, "")
+			printTwoCols(w, subcmd.name, subcmd.help, "", "")
 		}
 	}
 }
@@ -204,7 +219,7 @@ func (p *Parser) printOption(w io.Writer, spec *spec) {
 	if spec.short != "" {
 		left += ", " + synopsis(spec, "-"+spec.short)
 	}
-	printTwoCols(w, left, spec.help, spec.defaultVal)
+	printTwoCols(w, left, spec.help, spec.defaultVal, spec.env)
 }
 
 func synopsis(spec *spec, form string) string {
diff --git a/usage_test.go b/usage_test.go
index 35745f7..5d379a1 100644
--- a/usage_test.go
+++ b/usage_test.go
@@ -33,9 +33,9 @@ func (n *NameDotName) MarshalText() (text []byte, err error) {
 }
 
 func TestWriteUsage(t *testing.T) {
-	expectedUsage := "Usage: example [--name NAME] [--value VALUE] [--verbose] [--dataset DATASET] [--optimize OPTIMIZE] [--ids IDS] [--values VALUES] [--workers WORKERS] [--file FILE] INPUT [OUTPUT [OUTPUT ...]]\n"
+	expectedUsage := "Usage: example [--name NAME] [--value VALUE] [--verbose] [--dataset DATASET] [--optimize OPTIMIZE] [--ids IDS] [--values VALUES] [--workers WORKERS] [--testenv TESTENV] [--file FILE] INPUT [OUTPUT [OUTPUT ...]]\n"
 
-	expectedHelp := `Usage: example [--name NAME] [--value VALUE] [--verbose] [--dataset DATASET] [--optimize OPTIMIZE] [--ids IDS] [--values VALUES] [--workers WORKERS] [--file FILE] INPUT [OUTPUT [OUTPUT ...]]
+	expectedHelp := `Usage: example [--name NAME] [--value VALUE] [--verbose] [--dataset DATASET] [--optimize OPTIMIZE] [--ids IDS] [--values VALUES] [--workers WORKERS] [--testenv TESTENV] [--file FILE] INPUT [OUTPUT [OUTPUT ...]]
 
 Positional arguments:
   INPUT
@@ -51,7 +51,8 @@ Options:
   --ids IDS              Ids
   --values VALUES        Values [default: [3.14 42 256]]
   --workers WORKERS, -w WORKERS
-                         number of workers to start
+                         number of workers to start [default: 10, env: WORKERS]
+  --testenv TESTENV, -a TESTENV [env: TEST_ENV]
   --file FILE, -f FILE   File with mandatory extension [default: scratch.txt]
   --help, -h             display this help and exit
 `
@@ -65,7 +66,8 @@ Options:
 		Optimize int          `arg:"-O" help:"optimization level"`
 		Ids      []int64      `help:"Ids"`
 		Values   []float64    `help:"Values"`
-		Workers  int          `arg:"-w,env:WORKERS" help:"number of workers to start"`
+		Workers  int          `arg:"-w,env:WORKERS" help:"number of workers to start" default:"10"`
+		TestEnv  string       `arg:"-a,env:TEST_ENV"`
 		File     *NameDotName `arg:"-f" help:"File with mandatory extension"`
 	}
 	args.Name = "Foo Bar"