Add some useful benchmarks (#72)

TODO.md

@@ -11,7 +11,7 @@ Things I want to do to make this library as good as it can be and a better, simp
 - [x] Rename `cmd.example` to `cmd.examples`
 - [x] Clean up/rewrite some of the functions borrowed from Cobra e.g. `argsMinusFirstX`
 - [ ] Clean up and optimise the parsing logic
-- [ ] Do some benchmarking and see where we can improve
+- [x] Do some benchmarking and see where we can improve
 - [x] Remove the `Loop` tag from parsing functions
 - [ ] More full test programs as integration tests
 - [ ] Write a package example doc

command_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	goflag "flag"
 	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 	"slices"
@@ -626,3 +627,55 @@ func TestExecuteNonRootCommand(t *testing.T) {
 		test.Equal(t, err.Error(), "Execute must be called on the root of the command tree, was called on sub")
 	}
 }
+
+func BenchmarkExecuteHelp(b *testing.B) {
+	sub1, err := cli.New(
+		"sub1",
+		cli.Short("Do one thing"),
+		cli.Run(func(cmd *cli.Command, args []string) error {
+			fmt.Fprintln(cmd.Stdout(), "Hello from sub1")
+			return nil
+		}),
+	)
+	test.Ok(b, err)
+
+	sub2, err := cli.New(
+		"sub2",
+		cli.Short("Do another thing"),
+		cli.Run(func(cmd *cli.Command, args []string) error {
+			fmt.Fprintln(cmd.Stdout(), "Hello from sub2")
+			return nil
+		}),
+	)
+	test.Ok(b, err)
+
+	sub3, err := cli.New(
+		"very-long-subcommand",
+		cli.Short("Wow so long"),
+		cli.Run(func(cmd *cli.Command, args []string) error {
+			fmt.Fprintln(cmd.Stdout(), "Hello from sub3")
+			return nil
+		}),
+	)
+	test.Ok(b, err)
+
+	cmd, err := cli.New(
+		"bench-help",
+		cli.Short("A helpful benchmark command"),
+		cli.Long("Much longer text..."),
+		cli.Example("Do a thing", "bench-help very-long-subcommand --flag"),
+		cli.SubCommands(sub1, sub2, sub3),
+		cli.Args([]string{"--help"}),
+		cli.Stderr(io.Discard),
+		cli.Stdout(io.Discard),
+	)
+	test.Ok(b, err)
+
+	b.ResetTimer()
+	for range b.N {
+		err := cmd.Execute()
+		if err != nil {
+			b.Fatalf("Execute returned an error: %v", err)
+		}
+	}
+}

internal/flag/flag_test.go

@@ -648,3 +648,17 @@ func TestFlagNilSafety(t *testing.T) {
 		test.Equal(t, err.Error(), "cannot set value true, flag.value was nil")
 	})
 }
+
+func BenchmarkFlagSet(b *testing.B) {
+	var count int
+	flag, err := flag.New(&count, "count", 'c', 0, "Count things")
+	test.Ok(b, err)
+
+	b.ResetTimer()
+	for range b.N {
+		err := flag.Set("42")
+		if err != nil {
+			b.Fatalf("flag.Set returned an error: %v", err)
+		}
+	}
+}

internal/flag/set_test.go

@@ -1205,3 +1205,34 @@ func TestUsage(t *testing.T) {
 		})
 	}
 }
+
+func BenchmarkParse(b *testing.B) {
+	set := flag.NewSet()
+	f, err := flag.New(new(int), "count", 'c', 0, "Count something")
+	test.Ok(b, err)
+
+	f2, err := flag.New(new(bool), "delete", 'd', false, "Delete something")
+	test.Ok(b, err)
+
+	f3, err := flag.New(new(string), "name", 'n', "", "Name something")
+	test.Ok(b, err)
+
+	err = flag.AddToSet(set, f)
+	test.Ok(b, err)
+
+	err = flag.AddToSet(set, f2)
+	test.Ok(b, err)
+
+	err = flag.AddToSet(set, f3)
+	test.Ok(b, err)
+
+	args := []string{"some", "args", "here", "--delete", "--count", "10", "--name", "John"}
+
+	b.ResetTimer()
+	for range b.N {
+		err := set.Parse(args)
+		if err != nil {
+			b.Fatalf("Parse returned an error: %v", err)
+		}
+	}
+}