https://dtsx.netlify.app/assets/features_type-inference.md.BOqlkpBE.js

1import{_ as i,i as a,o as n,ak as e}from"./chunks/framework.Da91f1N-.js";const y=JSON.parse('{"title":"Type Inference","description":"","frontmatter":{},"headers":[],"relativePath":"features/type-inference.md","filePath":"features/type-inference.md"}'),t={name:"features/type-inference.md"};function h(l,s,p,k,r,d){return n(),a("div",null,s[0]||(s[0]=[e(`<h1 id="type-inference" tabindex="-1">Type Inference <a class="header-anchor" href="#type-inference" aria-label="Permalink to &quot;Type Inference&quot;">​</a></h1><p>dtsx provides powerful type inference capabilities to automatically determine types from your code.</p><h2 id="basic-type-inference" tabindex="-1">Basic Type Inference <a class="header-anchor" href="#basic-type-inference" aria-label="Permalink to &quot;Basic Type Inference&quot;">​</a></h2><h3 id="literal-types" tabindex="-1">Literal Types <a class="header-anchor" href="#literal-types" aria-label="Permalink to &quot;Literal Types&quot;">​</a></h3><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span><pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// String literal</span></span>
2<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> name</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> &quot;John&quot;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;  </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// type: &quot;John&quot;</span></span>
3<span class="line"></span>
4<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// Number literal</span></span>
5<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> age</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> 25</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;       </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// type: 25</span></span>
6<span class="line"></span>
7<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// Boolean literal</span></span>
8<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> isActive</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> true</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">; </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// type: true</span></span></code></pre></div><h3 id="array-types" tabindex="-1">Array Types <a class="header-anchor" href="#array-types" aria-label="Permalink to &quot;Array Types&quot;">​</a></h3><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span><pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// Array of numbers</span></span>
9<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> numbers</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> [</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">1</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">2</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">3</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">];  </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// type: number[]</span></span>
10<span class="line"></span>
11<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// Tuple type</span></span>
12<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> tuple</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> [</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">1</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">&quot;hello&quot;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">]; </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// type: [number, string]</span></span></code></pre></div><h3 id="object-types" tabindex="-1">Object Types <a class="header-anchor" href="#object-types" aria-label="Permalink to &quot;Object Types&quot;">​</a></h3><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span>

12<pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> user</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> {</span></span>
13<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">  name: </span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">&quot;John&quot;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">,</span></span>
14<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">  age: </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">25</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">,</span></span>
15<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">  active: </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">true</span></span>
16<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}; </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// type: { name: string; age: number; active: boolean; }</span></span></code></pre></div><h2 id="advanced-type-inference" tabindex="-1">Advanced Type Inference <a class="header-anchor" href="#advanced-type-inference" aria-label="Permalink to &quot;Advanced Type Inference&quot;">​</a></h2><h3 id="function-return-types" tabindex="-1">Function Return Types <a class="header-anchor" href="#function-return-types" aria-label="Permalink to &quot;Function Return Types&quot;">​</a></h3><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span><pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">function</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> process</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">&lt;</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">T</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">&gt;(</span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">input</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> T</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">) {</span></span>
17<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">  return</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> input;</span></span>
18<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">} </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// Return type: T</span></span>
19<span class="line"></span>
20<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">async</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> function</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> fetchData</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">() {</span></span>
21<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">  return</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> await</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> api.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">

21get</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">&#39;/data&#39;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">);</span></span>
22<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">} </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// Return type: Promise&lt;ApiResponse&gt;</span></span></code></pre></div><h3 id="generic-type-inference" tabindex="-1">Generic Type Inference <a class="header-anchor" href="#generic-type-inference" aria-label="Permalink to &quot;Generic Type Inference&quot;">​</a></h3><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span><pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">function</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> map</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">&lt;</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">T</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">U</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">&gt;(</span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">arr</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> T</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">[], </span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">fn</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> (</span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">item</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> T</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">) </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">=&gt;</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> U</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">)</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> U</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">[] {</span></span>
23<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">  return</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> arr.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">map</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(fn);</span></span>
24<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span>
25<span class="line"></span>
26<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// Usage</span></span>
27<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> numbers</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> [</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">1</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">2</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">3</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">];</span></span>
28<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> strings</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> map</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(numbers, </span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">n</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =&gt;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> n.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">toString</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">());</span></span>
29<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// strings type: string[]</span></span></code></pre></div><h3 id="union-type-inference" tabindex="-1">Union Type Inference <a class="header-anchor" href="#union-type-inference" aria-label="Permalink to &quot;Union Type Inference&quot;">​</a></h3><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span>

29<pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">function</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> processValue</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">value</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> string</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> |</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> number</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">) {</span></span>
30<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">  if</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> (</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">typeof</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> value </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">===</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> &#39;string&#39;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">) {</span></span>
31<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">    return</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> value.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">toUpperCase</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(); </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// type: string</span></span>
32<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">  }</span></span>
33<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">  return</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> value.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">toFixed</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;">2</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">); </span><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// type: string</span></span>
34<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre></div><h2 id="type-inference-features" tabindex="-1">Type Inference Features <a class="header-anchor" href="#type-inference-features" aria-label="Permalink to &quot;Type Inference Features&quot;">​</a></h2><h3 id="contextual-typing" tabindex="-1">Contextual Typing <a class="header-anchor" href="#contextual-typing" aria-label="Permalink to &quot;Contextual Typing&quot;">​</a></h3><ul><li>Function parameters</li><li>Object literals</li><li>Array literals</li><li>Class members</li><li>Interface implementations</li></ul><h3 id="type-narrowing" tabindex="-1">Type Narrowing <a class="header-anchor" href="#type-narrowing" aria-label="Permalink to &quot;Type Narrowing&quot;">​</a></h3><ul><li>Type guards</li><li>Control flow analysis</li><li>Discriminated unions</li><li>Property checks</li></ul><h3 id="type-widening" tabindex="-1">Type Widening <a class="header-anchor" href="#type-widening" aria-label="Permalink to &quot;Type Widening&quot;">​</a></h3><ul><li>Literal to primitive</li><li>Union type expansion</li><li>Const assertions</li><li>Type assertions</li></ul><h2 id="best-practices" tabindex="-1">Best Practices <a class="header-anchor" href="#best-practices" aria-label="Permalink to &quot;Best Practices&quot;">​</a></h2><ol><li><p><strong>Use Type Annotations When Needed</strong></p><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span><pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// When inference might be too specific</span></span>
35<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> config</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> Config</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> {</span></span>
36<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">

36  // ...</span></span>
37<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">};</span></span></code></pre></div></li><li><p><strong>Leverage Const Assertions</strong></p><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span><pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> colors</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> [</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">&#39;red&#39;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">&#39;green&#39;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">, </span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;">&#39;blue&#39;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">] </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">as</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> const</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
38<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// type: readonly [&quot;red&quot;, &quot;green&quot;, &quot;blue&quot;]</span></span></code></pre></div></li><li><p><strong>Use Type Guards</strong></p><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span><pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">function</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> isUser</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(</span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">value</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> unknown</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">)</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;"> value</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> is</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> User</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> {</span></span>
39<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">  return</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> typeof</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> value </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">===</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> &#39;object&#39;</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> &amp;&amp;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> value </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">!==</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> null</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> &amp;&amp;</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> &#39;name&#39;</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> in</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> value;</span></span>
40<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre></div></li><li><p><strong>Avoid Type Assertions</strong></p><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span>

40<pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// Prefer this</span></span>
41<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> value</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> process</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(input);</span></span>
42<span class="line"></span>
43<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">// Over this</span></span>
44<span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">const</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> value</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> =</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> process</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">(input) </span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">as</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> string</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span></code></pre></div></li></ol><h2 id="configuration" tabindex="-1">Configuration <a class="header-anchor" href="#configuration" aria-label="Permalink to &quot;Configuration&quot;">​</a></h2><div class="language-typescript vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">typescript</span><pre class="shiki shiki-themes github-light github-dark vp-code" style="--shiki-light:#24292e;--shiki-dark:#e1e4e8;--shiki-light-bg:#fff;--shiki-dark-bg:#24292e;" tabindex="0"><code><span class="line"><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">interface</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> TypeInferenceConfig</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;"> {</span></span>
45<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">  // Enable/disable type inference</span></span>
46<span class="line"><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">  enableInference</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#005CC5;--shiki-dark:#79B8FF;"> boolean</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
47<span class="line"></span>
48<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">  // Inference strictness level</span></span>
49<span class="line"><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">  strictness</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> &#39;loose&#39;</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> |</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> &#39;strict&#39;</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;"> |</span><span style="--shiki-light:#032F62;--shiki-dark:#9ECBFF;"> &#39;very-strict&#39;</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">;</span></span>
50<span class="line"></span>
51<span class="line"><span style="--shiki-light:#6A737D;--shiki-dark:#6A737D;">  // Custom inference rules</span></span>
52<span class="line"><span style="--shiki-light:#E36209;--shiki-dark:#FFAB70;">  customRules</span><span style="--shiki-light:#D73A49;--shiki-dark:#F97583;">:</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;"> InferenceRule</span><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">[];</span></span>
53<span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">}</span></span></code></pre></div>`,27)]))}const E=i(t,[["render",h]]);export{y as __pageData,E as default};