Add Fill An Input With A Ton Of Text as a javascript til

javascript/fill-an-input-with-a-ton-of-text.md

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+# Fill An Input With A Ton Of Text
+
+I needed to test out a form validation for an input that should render an
+error when the length of the context exceeds 10,000 characters. Two small
+tricks make this easy.
+
+First, you can target any DOM element via the Chrome dev tools by selecting
+it and then referencing it via the `$0` magic variable. [More details
+here](https://developers.google.com/web/updates/2015/05/the-currently-selected-dom-node).
+
+```javascript
+> $0
+<input>...</input>
+```
+
+Second, you can quickly and precisely generate a very long string with the
+`repeat` function.
+
+```javascript
+> "a".repeat(10000)
+"aaaaaaaaaaaaaaaaaaaaaaa..."
+```
+
+Combine these two tricks in the browser to fill the input with a ton of
+text:
+
+```javascript
+> $0.value = "a".repeat(10000)
+```
+
+h/t Dillon Hafer