From 8e20204948551fe73db9074415b2976083146307 Mon Sep 17 00:00:00 2001
From: Alberto Ricart <alberto@synadia.com>
Date: Wed, 7 Apr 2021 20:50:52 -0500
Subject: [PATCH] showed use of `persistent` flags.

---
 README.md | 29 ++++++++++++++++++++++++++++-
 main.ts   | 28 ++++++++++++----------------
 2 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/README.md b/README.md
index 5b3a6a5..1a156c1 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,13 @@ import { cli } from "https://deno.land/x/cobra/mod.ts";
 
 // create the root command
 const root = cli({ use: "greeting (hello|goodbye) [--name name] [--strong]" });
+root.addFlag({
+  short: "s",
+  name: "strong",
+  type: "boolean",
+  usage: "say message strongly",
+  persistent: true,
+});
 // add a subcommand
 const hello = root.addCommand({
   use: "hello --name string [--strong]",
@@ -39,13 +46,20 @@ const hello = root.addCommand({
   // and an object to let you access relevant flags.
   run: (cmd, args, flags): Promise<number> => {
     const strong = (flags.value<boolean>("strong") ?? false) ? "!!!" : "";
-    const n = flags.value<string>("name") ?? "mystery person";
+    let n = flags.value<string>("name");
+    n = n === "" ? "mystery person" : n;
     cmd.stdout(`hello ${n}${strong}`);
     return Promise.resolve(0);
   },
 });
 ```
 
+To execute the cli, simply `root.execute()` with arguments:
+
+```typescript
+Deno.exit(await root.execute(Deno.args));
+```
+
 The return of the command is a `Promise<number>` which is a number you can use
 to provide to the `Deno.exit(n)` function.
 
@@ -87,6 +101,19 @@ hello.addFlag({
 });
 ```
 
+Processing flags is similarly trivial:
+
+```typescript
+const n = flags.value<string>("name");
+```
+
+The value returned will be the one entered by the user, or the specified default
+in the configuration for the default value for the type - `""` or `false` or
+`0`.
+
+Flags marked as `persistent` can be associated with a container command and are
+available to all subcommands, reducing code duplication.
+
 ## Running your commands
 
 Once you build your command tree and related, flags, you simply call the root
diff --git a/main.ts b/main.ts
index 73c2290..391efa6 100644
--- a/main.ts
+++ b/main.ts
@@ -2,6 +2,13 @@ import { cli } from "./mod.ts";
 
 // create the root command
 const root = cli({ use: "greeting (hello|goodbye) [--name name] [--strong]" });
+root.addFlag({
+  short: "s",
+  name: "strong",
+  type: "boolean",
+  usage: "say message strongly",
+  persistent: true,
+});
 // add a subcommand
 const hello = root.addCommand({
   use: "hello --name string [--strong]",
@@ -11,31 +18,26 @@ const hello = root.addCommand({
   // and an object to let you access relevant flags.
   run: (cmd, args, flags): Promise<number> => {
     const strong = (flags.value<boolean>("strong") ?? false) ? "!!!" : "";
-    const n = flags.value<string>("name") ?? "mystery person";
+    let n = flags.value<string>("name");
+    n = n === "" ? "mystery person" : n;
     cmd.stdout(`hello ${n}${strong}`);
     return Promise.resolve(0);
   },
 });
-
 hello.addFlag({
   short: "n",
   name: "name",
   type: "string",
   usage: "name to say hello to",
 });
-hello.addFlag({
-  short: "s",
-  name: "strong",
-  type: "boolean",
-  usage: "say hello strongly",
-});
 
 const goodbye = root.addCommand({
   use: "goodbye --name string [--strong]",
   short: "says goodbye",
   run: (cmd, args, flags): Promise<number> => {
-    const strong = flags.value<boolean>("strong") ? "!!!" : "";
-    const n = flags.value<string>("name") ?? "mystery person";
+    const strong = (flags.value<boolean>("strong") ?? false) ? "!!!" : "";
+    let n = flags.value<string>("name");
+    n = n === "" ? "mystery person" : n;
     cmd.stdout(`goodbye ${n}${strong}`);
     return Promise.resolve(0);
   },
@@ -46,11 +48,5 @@ goodbye.addFlag({
   type: "string",
   usage: "name to say goodbye to",
 });
-goodbye.addFlag({
-  short: "s",
-  name: "strong",
-  type: "boolean",
-  usage: "say goodbye strongly",
-});
 
 Deno.exit(await root.execute(Deno.args));