fix(command): optional arguments are validated also if they are not s…

…pecified on the command line (#101)

command/command.ts

@@ -1006,7 +1006,10 @@ export class Command<O = any, A extends Array<any> = any> {
         }
       } else {
         for (const expectedArg of this.getArguments()) {
-          if (!expectedArg.optionalValue && !args.length) {
+          if (!args.length) {
+            if (expectedArg.optionalValue) {
+              break;
+            }
             throw this.error(
               new Error(`Missing argument: ${expectedArg.name}`),
             );
@@ -1029,7 +1032,7 @@ export class Command<O = any, A extends Array<any> = any> {
               label: "Argument",
               type: expectedArg.type,
               name: expectedArg.name,
-              value: args.shift() ?? "",
+              value: args.shift() as string,
             });
           }
 
@@ -1085,10 +1088,10 @@ export class Command<O = any, A extends Array<any> = any> {
   }
 
   /**
-     * Get parent command from global executed command.
-     * Be sure, to call this method only inside an action handler. Unless this or any child command was executed,
-     * this method returns always undefined.
-     */
+   * Get parent command from global executed command.
+   * Be sure, to call this method only inside an action handler. Unless this or any child command was executed,
+   * this method returns always undefined.
+   */
   public getGlobalParent(): Command | undefined {
     return this._globalParent;
   }

command/test/command/arguments_test.ts

@@ -11,8 +11,9 @@ function cmd() {
           `${label} ${name} must be a valid ${type} but got: ${value}`,
         );
       }
+      return value;
     })
-    .arguments("[foo:string] [bar:number] [baz:boolean] [color:color]");
+    .arguments("<foo:string> [bar:number] [baz:boolean] [color:color]");
 }
 
 Deno.test("'-' as argument", async () => {
@@ -24,7 +25,7 @@ Deno.test("'-' as argument", async () => {
 
 Deno.test("valid command argument types", async () => {
   const { args } = await cmd().parse(["abc", "123", "true", "red"]);
-  assertEquals(args, ["abc", 123, true]);
+  assertEquals(args, ["abc", 123, true, "red"]);
 });
 
 Deno.test("invalid number command argument type", async () => {
@@ -37,6 +38,16 @@ Deno.test("invalid number command argument type", async () => {
   );
 });
 
+Deno.test("missing command arguments", async () => {
+  await assertThrowsAsync(
+    async () => {
+      await cmd().parse();
+    },
+    Error,
+    "Missing argument(s): foo",
+  );
+});
+
 Deno.test("invalid boolean command argument type", async () => {
   await assertThrowsAsync(
     async () => {