Trim Left
2021-05-10
Today we discuss Trim Left
String.prototype.trimStart does the same in JavaScript what we are about to do in TypeScript.
Let's try 👩💻
Iteration over a string
We already know how to iterate over:
- Object types (see Pick under the hood)
- Tuple types (see Making object out of tuple)
- Union types (see Exclude under the hood)
For strings we need several concepts:
- Type inference in conditional types to infer substrings without whitespaces.
- Template Literal types to match substrings in a string.
First, let's declare Whitespace which will be removed from the beginning:
Second, let's try to remove the first whitespace if it is a part of a string we pass. We will get something like this:
Not all test cases are completed because we don't remove whitespaces after the first one. Let's apply the type recursively:
That's it 💪
The solution is available in Playground
Have a good day and week 🌤
typescript