feat(cli): add help message and usage documentation

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "issue-scheduler",
-	"description": "Schedule issues in Gitea or Github from issue templates",
+	"description": "Schedule issues in Gitea or GitHub using issue templates",
 	"version": "0.0.0",
 	"main": "dist/index.js",
 

src/cli.ts

@@ -8,6 +8,10 @@ export interface CLIConfig {
     // doesn't log to stdout/stderr (still logs to file if --log-file)
     quiet: boolean
 }
+// TODO: Git client shouldn't be identified from the config,
+// but from the host url or a custom config property
+// TODO: add --list-issue-templates <user> <repo> <token> : list results from api.getIssueTemplates
+// TODO: add other utility commands
 
 export const defaults: CLIConfig = {
     config_filepath: "config.toml",
@@ -97,14 +101,37 @@ export function optionalBooleanFlag(args: string[], flags: string[]): boolean {
     return value === null;
 }
 
+const Usage = (program_name: string) => `\
+Usage: ${program_name} [options...]
+
+Issue Scheduler - Schedule issues in Gitea or GitHub using issue templates
+
+Options:
+    -h, --help                  Display this message
+    -c, --config <filepath>     Config file [default: "config.toml"]
+    -l, --log-file <filepath>   Logs output to file
+    -v, --verbose               Verbose logging
+    -q, --quiet                 Only logs to --log-file (if provided)
+`
+
 /**
  * Parse command line arguments from a string array (process.argv)
  * @param args Command line arguments
  * @return {CLIConfig} Parsed flags
  */
 export function parseArgs(args: string[]): CLIConfig {
+    if (args.length < 2) { // [node executable, program path, ...]
+        // TODO: log error
+        process.exit(1)
+    }
     const config = defaults
 
+    const helpValue = optionalBooleanFlag(args, ["--help", "-h"])
+    if (helpValue) {
+        console.log(Usage(args[1]!))
+        process.exit(0)
+    }
+
     const configValue = optionalStringFlag(args, ["--config", "-c"])
     if (configValue) config.config_filepath = configValue