Fix multi-line arg and option usage

CHANGELOG.md

@@ -4,6 +4,12 @@ This project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html
 
 ## Unreleased
 
+## 0.7.3 (2025-01-05)
+
+### Fixed
+
+- Handle multi-line usage for args and options in help text.
+
 ## 0.7.2 (2025-01-05)
 
 ### Added

appcli/help.go

@@ -209,7 +209,7 @@ Arguments:
 }
 
 func formatArg(arg *runner.Arg, width int) string {
-	line := pad(arg.Name, width) + arg.Usage
+	line := pad(arg.Name, width) + formatUsage(arg.Usage, width)
 
 	if len(arg.ValuesAllowed) > 0 {
 		if arg.Usage != "" {
@@ -271,7 +271,7 @@ Options:
 }
 
 func formatOpt(flag cli.Flag, opt *runner.Option, width int) string {
-	line := pad(flagPrefix(flag, opt), width) + unquoteUsage(opt.Usage)
+	line := pad(flagPrefix(flag, opt), width) + formatUsage(opt.Usage, width)
 	defaultValue, hasDefault := opt.StaticDefault()
 
 	if hasDefault {
@@ -305,11 +305,17 @@ func maxOptionWidth(command *cli.Command, opts []*runner.Option) int {
 func flagPrefix(flag cli.Flag, opt *runner.Option) string {
 	text := cli.FlagStringer(flag)
 	if opt.Usage != "" {
-		text, _, _ = strings.Cut(text, unquoteUsage(opt.Usage))
+		text, _, _ = strings.Cut(text, strings.TrimSpace(unquoteUsage(opt.Usage)))
 	}
 	return strings.TrimRight(text, " \t")
 }
 
+func formatUsage(usage string, width int) string {
+	usage = unquoteUsage(usage)
+	indent := strings.Repeat(" ", width+3)
+	return strings.TrimSpace(strings.ReplaceAll(usage, "\n", "\n"+indent))
+}
+
 // Unquotes placeholder text from the usage string.
 //
 // Modified from urfave/cli.

main_test.go

@@ -95,6 +95,7 @@ Description:
 Arguments:
    short        The first argument
    longer-name  The second argument
+                which is multi-line
                 One of: foo, bar
    no-details
    values-only  One of: baz, qux
@@ -103,6 +104,7 @@ Options:
        --bool-default-true        Boolean value (default: true)
    -b, --brief                    A brief flag
        --much-less-brief <value>  A much less brief flag
+                                  which is multi-line
                                   One of: baz, qux
        --numeric <value>          This is numeric (default: 0)
        --only-default <value>     Default: some-default

testdata/help.yml

@@ -31,7 +31,9 @@ tasks:
       short:
         usage: The first argument
       longer-name:
-        usage: The second argument
+        usage: |
+          The second argument
+          which is multi-line
         values:
           - foo
           - bar
@@ -53,7 +55,9 @@ tasks:
       placeholder:
         usage: With a value named `val`
       much-less-brief:
-        usage: A much less brief flag
+        usage: |
+          A much less brief flag
+          which is multi-line
         values:
           - baz
           - qux