Implement check-depends --help and refactor help texts for easier maintenance

check_depends.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"log"
 	"os"
@@ -19,6 +20,31 @@ type dependency struct {
 }
 
 func execCheckDepends(args []string) {
+	fs := flag.NewFlagSet("check-depends", flag.ExitOnError)
+	fs.Usage = func() {
+		fmt.Fprintf(os.Stderr, `Usage: %s check-depends
+
+Compares the Go module dependencies in go.mod against
+the Debian packages available in the archive.
+
+Reports:
+  NEW: Dependencies in go.mod not yet packaged in Debian
+  RM:  Debian packages in d/control no longer needed by go.mod
+
+This command takes no arguments.
+`, os.Args[0])
+	}
+
+	err := fs.Parse(args)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if fs.NArg() > 0 {
+		fs.Usage()
+		os.Exit(1)
+	}
+
 	cwd, err := os.Getwd()
 	if err != nil {
 		log.Fatalf("error while getting current directory: %s", err)

check_depends_test.go

@@ -2,8 +2,10 @@ package main
 
 import (
 	"os"
+	"os/exec"
 	"path/filepath"
 	"reflect"
+	"strings"
 	"testing"
 )
 
@@ -138,3 +140,31 @@ require (
 		t.Fatalf("Wrong dependencies returned (got %v want %v)", deps, want)
 	}
 }
+
+func TestCheckDependsHelp(t *testing.T) {
+	// Test that --help flag works and shows usage information
+	// We run via 'go run' to avoid needing a pre-built binary
+	cmd := exec.Command("go", "run", ".", "check-depends", "--help")
+	output, err := cmd.CombinedOutput()
+
+	// The -help flag causes flag.ExitOnError to exit with code 0, which exec sees as nil error
+	if err != nil {
+		t.Fatalf("check-depends --help failed: %v\nOutput: %s", err, string(output))
+	}
+
+	outputStr := string(output)
+	expectedStrings := []string{
+		"Usage:",
+		"check-depends",
+		"go.mod",
+		"d/control",
+		"NEW:",
+		"RM:",
+	}
+
+	for _, expected := range expectedStrings {
+		if !strings.Contains(outputStr, expected) {
+			t.Errorf("Help output missing expected string %q\nFull output:\n%s", expected, outputStr)
+		}
+	}
+}

main.go

@@ -15,24 +15,28 @@ var (
 )
 
 func usage() {
-	fmt.Fprintf(os.Stderr, "%s\n", buildVersionString())
-	fmt.Fprintf(os.Stderr, "\n")
-	fmt.Fprintf(os.Stderr, "%s is a tool that converts Go packages into Debian package source.\n", program)
-	fmt.Fprintf(os.Stderr, "\n")
-	fmt.Fprintf(os.Stderr, "Usage:\n\t%s [globalflags] <command> [flags] <args>\n", program)
-	fmt.Fprintf(os.Stderr, "\n")
-	fmt.Fprintf(os.Stderr, "%s commands:\n", program)
-	fmt.Fprintf(os.Stderr, "\tmake\t\t\tcreate a Debian package\n")
-	fmt.Fprintf(os.Stderr, "\tsearch\t\t\tsearch Debian for already-existing packages\n")
-	fmt.Fprintf(os.Stderr, "\testimate\t\testimate the amount of work for a package\n")
-	fmt.Fprintf(os.Stderr, "\tcreate-salsa-project\tcreate a project for hosting Debian packaging\n")
-	fmt.Fprintf(os.Stderr, "\tclone\t\t\tclone a Go package from Salsa\n")
-	fmt.Fprintf(os.Stderr, "\tcheck-depends\t\tcompare go.mod and d/control to check for changes\n")
-	fmt.Fprintf(os.Stderr, "\n")
-	fmt.Fprintf(os.Stderr, "For backwards compatibility, when no command is specified,\nthe make command is executed.\n")
-	fmt.Fprintf(os.Stderr, "\n")
-	fmt.Fprintf(os.Stderr, "To learn more about a command, run \"%s <command> -help\",\ne.g. \"%s make -help\"\n", program, program)
-	fmt.Fprintf(os.Stderr, "\n")
+	fmt.Fprintf(os.Stderr, `%s
+
+%s is a tool that converts Go packages into Debian package source.
+
+Usage:
+	%s [globalflags] <command> [flags] <args>
+
+%s commands:
+	make			create a Debian package
+	search			search Debian for already-existing packages
+	estimate		estimate the amount of work for a package
+	create-salsa-project	create a project for hosting Debian packaging
+	clone			clone a Go package from Salsa
+	check-depends		compare go.mod and d/control to check for changes
+
+For backwards compatibility, when no command is specified,
+the make command is executed.
+
+To learn more about a command, run "%s <command> -help",
+e.g. "%s make -help"
+
+`, buildVersionString(), program, program, program, program, program)
 }
 
 func main() {

search.go

@@ -58,9 +58,10 @@ func execSearch(args []string) {
 	fs := flag.NewFlagSet("search", flag.ExitOnError)
 
 	fs.Usage = func() {
-		fmt.Fprintf(os.Stderr, "Usage: %s search <pattern>\n", os.Args[0])
-		fmt.Fprintf(os.Stderr, "Uses Go's default regexp syntax (https://golang.org/pkg/regexp/syntax/)\n")
-		fmt.Fprintf(os.Stderr, "Example: %s search 'debi.*'\n", os.Args[0])
+		fmt.Fprintf(os.Stderr, `Usage: %s search <pattern>
+Uses Go's default regexp syntax (https://golang.org/pkg/regexp/syntax/)
+Example: %s search 'debi.*'
+`, os.Args[0], os.Args[0])
 	}
 
 	err := fs.Parse(args)

version_test.go

@@ -32,7 +32,8 @@ func TestSnapshotVersion(t *testing.T) {
 		t.Fatalf("Could not write temp file %q: %v", tempfile, err)
 	}
 
-	gitCmdOrFatal(t, tempdir, "init")
+	// Suppress git hint about default branch name by setting init.defaultBranch
+	gitCmdOrFatal(t, tempdir, "init", "--initial-branch=master")
 	gitCmdOrFatal(t, tempdir, "config", "user.email", "unittest@example.com")
 	gitCmdOrFatal(t, tempdir, "config", "user.name", "Unit Test")
 	gitCmdOrFatal(t, tempdir, "add", "test")