Add command line help

Author: Fred

README.md

@@ -170,19 +170,19 @@ As we saw earlier, for each test, you will have to define the expected result. o
 To launch okapi, please run the following:
 
 ```shell
-    okapi <options> test_directory
+    okapi [options] <test_directory>
 ```
 
 where options are one or more of the following:
 
-- `test_directory`: the directory where all the test files are located
-- `--servers-file` or `-s` (mandatory): allows to point to the configuration file
-- `--timeout` (default 30s): allows to set a default timeout for all HTTP requests
-- `--verbose` (`--no-verbose`) or `-v` (default no): verbose mode
-- `--parallel` (`--no-parallel`) or `-p` (default yes): run tests in parallel
-- `--user-agent` (default okapi ua): to set the default user agent
-- `--content-type` (default application/json): to set the default content type for requests
-- `--accept` (default application/json): to set the default accept header for responses
+- `--servers-file`, `-s` (mandatory): point to the configuration file's location
+- `--timeout` (default 30s): set a default timeout for all HTTP requests
+- `--verbose`, `-v` (default no): enable verbose mode
+- `--no-parallel` (default parallel): prevent tests from running in parallel
+- `--user-agent` (default okapi UA): set the default user agent
+- `--content-type` (default application/json): set the default content type for requests
+- `--accept` (default application/json): set the default accept header for responses
+- `test_directory`: point to the directory where all the test files are located
 
 ## Output example
 

main.go

@@ -2,13 +2,41 @@ package main
 
 import (
 	"context"
+	"fmt"
 	"log"
 	"os"
 
 	"github.com/fred1268/okapi/testing"
 )
 
+func help() {
+	fmt.Println("okapi is a tool to help make API tests as easy as table driven tests.")
+	fmt.Println()
+	fmt.Println("Usage:")
+	fmt.Println()
+	fmt.Println("\tokapi [options] <test_directory>")
+	fmt.Println()
+	fmt.Println("The options are:")
+	fmt.Println()
+	fmt.Println("\t--servers-file, -s (mandatory):\t\t\t\tpoint to the configuration file's location")
+	fmt.Println("\t--timeout (default 30s):\t\t\t\tset a default timeout for all HTTP requests")
+	fmt.Println("\t--verbose, -v (default no):\t\t\t\tenable verbose mode")
+	fmt.Println("\t--no-parallel (default parallel):\t\t\tprevent tests from running in parallel")
+	fmt.Println("\t--user-agent (default okapi UA):\t\t\tset the default user agent")
+	fmt.Println("\t--content-type (default application/json):\t\tset the default content type for requests")
+	fmt.Println("\t--accept (default application/json):\t\t\tset the default accept header for responses")
+	fmt.Println()
+	fmt.Println("The parameters are:")
+	fmt.Println()
+	fmt.Println("\ttest_directory:\t\t\t\t\t\tpoint to the directory where all the test files are located")
+	fmt.Println()
+}
+
 func main() {
+	if len(os.Args) == 1 || len(os.Args) > 1 && (os.Args[1] == "--help" || os.Args[1] == "help" || os.Args[1] == "-h") {
+		help()
+		return
+	}
 	cfg, err := testing.LoadConfig(os.Args)
 	if err != nil {
 		log.Fatalf("Cannot read command line parameters: %s\n", err)