From 294697330deb01521906c34b516d1c215edbbe2a Mon Sep 17 00:00:00 2001
From: Alberto Ricart <alberto@synadia.com>
Date: Tue, 24 Aug 2021 15:05:32 -0500
Subject: [PATCH] [FIX] when getting array values, the expected result is an
 empty array if a flag was not specified.

---
 mod.ts  |  3 ++-
 test.ts | 40 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/mod.ts b/mod.ts
index c8a48e3..5c2f095 100644
--- a/mod.ts
+++ b/mod.ts
@@ -103,7 +103,7 @@ export class FlagsImpl implements Flags {
     if (!f) {
       throw new Error(`unknown flag ${n}`);
     }
-    let v = f.value ?? f.default ?? this.defaultValue(f);
+    let v = f.value ?? [];
     if (!Array.isArray(v)) {
       v = [v];
     }
@@ -386,6 +386,7 @@ export class RootCommand extends Command implements Execute {
     // deno-lint-ignore no-explicit-any
     const parseOpts = { "--": true } as any;
     flags.forEach((f) => {
+      f.value = null;
       const key = f.short.length ? f.short : f.name;
 
       if (f.short && f.name) {
diff --git a/test.ts b/test.ts
index 18db1a7..88bc854 100644
--- a/test.ts
+++ b/test.ts
@@ -1,5 +1,6 @@
 import {
   assert,
+  assertArrayIncludes,
   assertEquals,
   assertThrows,
 } from "https://deno.land/std/testing/asserts.ts";
@@ -221,13 +222,13 @@ Deno.test("flags - array values returns array", async () => {
   assertEquals(rv, 0);
 });
 
-Deno.test("flags - array values returns default", async () => {
+Deno.test("flags - array values returns empty", async () => {
   const root = cli({ use: "test" });
   const t = root.addCommand({
     use: "t",
     run: (_cmd, _args, flags): Promise<number> => {
       const v = flags.values<number>("x");
-      assertEquals(v, [0]);
+      assertEquals(v, []);
       return Promise.resolve(0);
     },
   });
@@ -260,3 +261,38 @@ Deno.test("flags - unknown values throws", async () => {
   const rv = await root.execute(["t"]);
   assertEquals(rv, 0);
 });
+
+Deno.test("flags - values with no value set returns empty", async () => {
+  const root = cli({ use: "test" });
+  let values: string[] = [];
+  const t = root.addCommand({
+    use: "t",
+    run: (_cmd, _args, flags): Promise<number> => {
+      values = flags.values<string>("v");
+      return Promise.resolve(0);
+    },
+  });
+  t.addFlag({
+    name: "v",
+    type: "string",
+  });
+
+  let rv = await root.execute(["t"]);
+  assertEquals(rv, 0);
+  console.log(values);
+  assertEquals(values.length, 0);
+
+  rv = await root.execute(["t", "--v", "a"]);
+  assertEquals(rv, 0);
+  assertEquals(values.length, 1);
+  assertArrayIncludes(values, ["a"]);
+
+  rv = await root.execute(["t", "--v", "a", "--v", "b"]);
+  assertEquals(rv, 0);
+  assertEquals(values.length, 2);
+  assertArrayIncludes(values, ["a", "b"]);
+
+  rv = await root.execute(["t"]);
+  assertEquals(rv, 0);
+  assertEquals(values.length, 0);
+});