Add Ignore All Errors In A TypeScript File as a TypeScript TIL

Author: jbranchaud

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1498 TILs and counting..._
+_1499 TILs and counting..._
 
 ---
 
@@ -1383,6 +1383,7 @@ _1498 TILs and counting..._
 - [Generate An Initial tsconfig File](typescript/generate-an-initial-tsconfig-file.md)
 - [Generate Inferred Type From Zod Schema](typescript/generate-inferred-type-from-zod-schema.md)
 - [Get The Return Type Of An Async Function](typescript/get-the-return-type-of-an-async-function.md)
+- [Ignore All Errors In A TypeScript File](typescript/ignore-all-errors-in-a-typescript-file.md)
 - [Interfaces With The Same Name Are Merged](typescript/interfaces-with-the-same-name-are-merged.md)
 - [Narrow The Type Of An Array To Its Values](typescript/narrow-the-type-of-an-array-to-its-values.md)
 - [Re-Export An Imported Type](typescript/re-export-an-imported-type.md)

typescript/ignore-all-errors-in-a-typescript-file.md

@@ -0,0 +1,35 @@
+# Ignore All Errors In A TypeScript File
+
+As of TypeScript 3.7, we can mark an entire TypeScript file to be ignored by
+the TypeScript compiler when it is doing static type checking.
+
+We can do this by adding the `@ts-nocheck` directive at the top of the file:
+
+```typescript
+// @ts-nocheck
+
+type User = {
+  id: string;
+  name: string;
+  email: string;
+}
+
+const user: User = {
+  id: 123,
+  name: "Liz Lemon",
+  email: "[email protected]",
+};
+```
+
+Notice that `id` is typed as a `string`, but we are using a `number` with `id`
+for `user`. That is a type error. But with the `@ts-nocheck` directive at the
+top, the type checker doesn't run on the file and we see no type errors.
+
+I'd generally suggest to avoid doing this. It can hide real type errors that
+you should be addressing. That said, in special circumstances, you may need it,
+even if just temporarily, like if an imported package doesn't have types. Here
+is an example of that in [uploadthing's
+`rehype.js`](https://github.com/pingdotgg/uploadthing/blob/d98fbefedddf64d183cc5a00b3fd707e8d8f2f6c/docs/src/mdx/rehype.js#L1)
+which is missing types from `mdx-annotations`.
+
+[source](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html#-ts-nocheck-in-typescript-files)