cli: add rad fork example test

Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett

radicle-cli/examples/rad-fork.md

@@ -0,0 +1,49 @@
+If we have fetched a project, then we do not have a fork of the
+repository in the storage, i.e. there is no ref hierarchy for our
+NID. This is demonstrated below where our NID is
+`z6Mkt67GdsW7715MEfRuP4pSZxJRJh6kj6Y48WRqVv4N1tRk`:
+
+```
+$ rad inspect rad:z42hL2jL4XNk6K8oHQaSWfMgCL7ji --refs
+.
+`-- z6MknSLrJoTcukLrE435hVNQT4JUhbvWLX4kUzqkEStBU8Vi
+    `-- refs
+        |-- heads
+        |   `-- master
+        `-- rad
+            |-- id
+            `-- sigrefs
+```
+
+To remedy this, we can use the `rad fork` command for the project we
+wish to fork:
+
+```
+$ rad fork rad:z42hL2jL4XNk6K8oHQaSWfMgCL7ji
+✓ Forked project rad:z42hL2jL4XNk6K8oHQaSWfMgCL7ji for z6Mkt67GdsW7715MEfRuP4pSZxJRJh6kj6Y48WRqVv4N1tRk
+```
+
+Now, if we `rad inspect` the project's refs again we will see that we
+have a copy of the main set of refs:
+
+```
+$ rad inspect rad:z42hL2jL4XNk6K8oHQaSWfMgCL7ji --refs
+.
+|-- z6MknSLrJoTcukLrE435hVNQT4JUhbvWLX4kUzqkEStBU8Vi
+|   `-- refs
+|       |-- heads
+|       |   `-- master
+|       `-- rad
+|           |-- id
+|           `-- sigrefs
+`-- z6Mkt67GdsW7715MEfRuP4pSZxJRJh6kj6Y48WRqVv4N1tRk
+    `-- refs
+        |-- heads
+        |   `-- master
+        `-- rad
+            |-- id
+            `-- sigrefs
+```
+
+We are now able to setup a remote in our own working copy of the
+project and push to our own fork.

radicle-cli/tests/commands.rs

@@ -428,6 +428,47 @@ fn rad_fetch() {
     .unwrap();
 }
 
+#[test]
+fn rad_fork() {
+    let mut environment = Environment::new();
+    let working = environment.tmp().join("working");
+    let alice = environment.node("alice");
+    let bob = environment.node("bob");
+
+    let mut alice = alice.spawn(Config::default());
+    let bob = bob.spawn(Config::default());
+
+    alice.connect(&bob);
+    fixtures::repository(working.join("alice"));
+
+    // Alice initializes a repo after her node has started, and after bob has connected to it.
+    test(
+        "examples/rad-init-sync.md",
+        &working.join("alice"),
+        Some(&alice.home),
+        [],
+    )
+    .unwrap();
+
+    // Wait for bob to get any updates to the routing table.
+    bob.converge([&alice]);
+
+    test(
+        "examples/rad-fetch.md",
+        working.join("bob"),
+        Some(&bob.home),
+        [],
+    )
+    .unwrap();
+    test(
+        "examples/rad-fork.md",
+        working.join("bob"),
+        Some(&bob.home),
+        [],
+    )
+    .unwrap();
+}
+
 #[test]
 // User tries to clone; no seeds are available, but user has the repo locally.
 fn test_clone_without_seeds() {