js type conversion reference (#63)

src/SUMMARY.md

@@ -33,6 +33,7 @@
 
 - [Anchor References](./anchor_references/anchor_references.md)
   - [Space Reference](./anchor_references/space.md)
+  - [Javascript Type Conversion Reference](./anchor_references/js_type_conversion_reference.md)
   - [CLI Reference](./anchor_references/cli.md)
   - [AVM Reference](./anchor_references/avm.md)
   - [Anchor.toml Reference](./anchor_references/anchor-toml_reference.md)

src/anchor_in_depth/milestone_project_tic-tac-toe.md

@@ -316,7 +316,7 @@ The structure of the transaction function is as follows: First come the instruct
 We did not have to specify the `system_program` account. This is because anchor recognizes this account and is able to infer it. This is also true for other known accounts such as the `token_program` or the `rent` sysvar account.
 
 After the transaction returns, we can fetch the state of the game account. You can fetch account state using the `program.account` namespace. 
-Finally, we verify the game has been set up properly. Anchor's typescript client deserializes rust enums like this: `{ active: {}}` for a fieldless variant and `{ won: { winner: Pubkey }}` for a variant with fields. The `None` variant of `Option` becomes `null`. The `Some(x)` variant becomes whatever `x` deserializes to.
+Finally, we verify the game has been set up properly by comparing the actual state and the expected state. To learn how Anchor maps the Rust types to the js/ts types, check out the [Javascript Type Conversion Reference](./../anchor_references/js_type_conversion_reference.md).
 
 Now, run `anchor test`. This starts up (and subsequently shuts down) a local validator (make sure you don't have one running before) and runs your tests using the test script defined in `Anchor.toml`.
 

src/anchor_references/js_type_conversion_reference.md

@@ -0,0 +1,148 @@
+# Javascript Type Conversion Reference
+
+This reference shows you how rust types are mapped to javascript/typescript types in the client.
+
+<table>
+<thead>
+    <tr>
+        <th>Rust Type</th>
+        <th>Javascript Type</th>
+        <th>Example</th>
+        <th>Note</th>
+    </tr>
+</thead>
+<tbody>
+    <tr>
+        <td>bool</td>
+        <td>bool</td>
+        <td >
+            <pre><code>await program
+    .methods
+    .init(true)
+    .rpc();</code></pre>
+        </td>
+        <td></td>
+    </tr>
+    <tr>
+        <td>u64/u128/i64/i128</td>
+        <td>anchor.BN</td>
+        <td >
+            <pre><code>await program
+    .methods
+    .init(new anchor.BN(99))
+    .rpc();</code></pre>
+        </td>
+        <td>
+            https://github.com/indutny/bn.js/
+        </td>
+    </tr>
+    <tr>
+        <td>u8/u16/u32/i8/i16/i32</td>
+        <td>number</td>
+        <td >
+            <pre><code>await program
+    .methods
+    .init(99)
+    .rpc();</code></pre>
+        </td>
+        <td></td>
+    </tr>
+    <tr>
+        <td>f32/f64</td>
+        <td>number</td>
+        <td >
+            <pre><code>await program
+    .methods
+    .init(1.0)
+    .rpc();</code></pre>
+        </td>
+        <td></td>
+    </tr>
+    <tr>
+        <td>Option&lt;T&gt;</td>
+        <td><code>null</code> or T</td>
+        <td >
+            <pre><code>await program
+    .methods
+    .init(null)
+    .rpc();</code></pre>
+        </td>
+        <td></td>
+    </tr>
+    <tr>
+        <td>Enum</td>
+        <td nowrap><code>{ variantName: {} }</code></td>
+        <td>
+            <pre><code>// Rust
+enum MyEnum { One, Two };
+// JS
+await program
+    .methods
+    .init({ one: {} })
+    .rpc();
+</code></pre>
+<pre><code>// Rust 
+enum MyEnum { One: { val: u64 }, Two };
+// JS
+await program
+    .methods
+    .init({ one: { val: 99 } })
+    .rpc();
+</code></pre>
+        </td>
+        <td>
+            No support for tuple variants
+        </td>
+    </tr>
+    <tr>
+        <td>Struct</td>
+        <td nowrap><code>{ val: {} }</code></td>
+        <td>
+<pre><code>// Rust
+struct MyStruct { val: u64 };
+// JS
+await program
+    .methods
+    .init({ val: 99 })
+    .rpc();
+</code></pre>
+        </td>
+        <td>
+            No support for tuple structs
+        </td>
+    </tr>
+    <tr>
+        <td>[T; N]</td>
+        <td>[ T ]</td>
+        <td >
+            <pre><code>await program
+    .methods
+    .init([1,2,3])
+    .rpc();</code></pre>
+        </td>
+        <td></td>
+    </tr>
+    <tr>
+        <td>String</td>
+        <td>string</td>
+        <td >
+            <pre><code>await program
+    .methods
+    .init("hello")
+    .rpc();</code></pre>
+        </td>
+        <td></td>
+    </tr>
+    <tr>
+        <td>Vec&lt;T&gt;</td>
+        <td>[ T ]</td>
+        <td >
+            <pre><code>await program
+    .methods
+    .init([1,2,3])
+    .rpc();</code></pre>
+        </td>
+        <td></td>
+    </tr>
+</tbody>
+</table>