new errors section

Author: basarat

SUMMARY.md

@@ -67,6 +67,9 @@
 * [Options](docs/options/intro.md)
   * [noImplicitAny](docs/options/noImplicitAny.md)
   * [strictNullChecks](docs/options/strictNullChecks.md)
+* [Errors in TypeScript](docs/errors/main.md)
+  * [Reading Errors](docs/errors/reading-errors.md)
+  * [Common Errors](docs/errors/common-errors.md)
 * [Testing](docs/testing/intro.md)
   * [Jest](docs/testing/jest.md)
   * [Cypress](docs/testing/cypress.md)
@@ -96,7 +99,6 @@
   * [Create Arrays](docs/tips/create-arrays.md)
   * [Typesafe Event Emitter](docs/tips/typed-event.md)
 * [StyleGuide](docs/styleguide/styleguide.md)
-* [Common Errors](docs/errors/main.md)
 * [TypeScript Compiler Internals](docs/compiler/overview.md)
   * [Program](docs/compiler/program.md)
   * [AST](docs/compiler/ast.md)

docs/errors/common-errors.md

@@ -0,0 +1,50 @@
+# Common Errors
+In this section we explain a number of common error codes that users experience in the real world.
+
+## TS2304
+Samples:
+> `Cannot find name ga`
+> `Cannot find name $`
+> `Cannot find module jquery`
+
+You are probably using a third party library (e.g. google analytics) and don't have it `declare`d. TypeScript tries to save you from *spelling mistakes* and *using variables without declaring them* so you need to be explicit on anything that is *available at runtime* because of you including some external library ([more on how to fix it][ambient]).
+
+## TS2307
+Samples:
+> `Cannot find module 'underscore'`
+
+You are probably using a third party library (e.g. underscore) as a *module* ([more on modules][modules]) and don't have the ambient declaration file for it ([more on ambient declarations][ambient]).
+
+## TS1148
+Sample:
+> Cannot compile modules unless the '--module' flag is provided
+
+Checkout the [section on modules][modules].
+
+## Catch clause variable cannot have a type annotation
+Sample:
+```js
+try { something(); }
+catch (e: Error) { // Catch clause variable cannot have a type annotation
+}
+```
+TypeScript is protecting you from JavaScript code in the wild being wrong. Use a type guard instead:
+```js
+try { something(); }
+catch (e) {
+  if (e instanceof Error){
+    // Here you go.
+  }
+}
+```
+
+## Interface `ElementClass` cannot simultaneously extend types `Component` and `Component`
+This happens when you have two `react.d.ts` (`@types/react/index.d.ts`) in the compilation context.
+
+**Fix**:
+* Delete `node_modules` and any `package-lock` (or yarn lock) and `npm install` again.
+* If it doesn't work, find the invalid module (all modules used by your project should have `react.d.ts` as a `peerDependency` and not a hard `dependency`) and report it on their project.
+
+
+[ambient]: ../types/ambient/d.ts.md
+[modules]: ../project/modules.md

docs/errors/main.md

@@ -1,55 +1,2 @@
-# Common Errors
-In this section we explain a number of common error codes that users experience in the real world.
-
-## TS2304
-Samples:
-> `Cannot find name ga`
-
-You are probably using a third party library (e.g. google analytics) and don't have it `declare`d. TypeScript tries to save you from *spelling mistakes* and *using variables without declaring them* so you need to be explicit on anything that is *available at runtime* because of you including some external library ([more on how to fix it][ambient]).
-
-## TS2307
-Samples:
-> `Cannot find module 'underscore'`
-
-You are probably using a third party library (e.g. underscore) as a *module* ([more on modules][modules]) and don't have the ambient declaration file for it ([more on ambient declarations][ambient]).
-
-## TS1148
-Sample:
-> Cannot compile modules unless the '--module' flag is provided
-
-Checkout the [section on modules][modules].
-
-## Catch clause variable cannot have a type annotation
-Sample:
-```js
-try { something(); }
-catch (e: Error) { // Catch clause variable cannot have a type annotation
-}
-```
-TypeScript is protecting you from JavaScript code in the wild being wrong. Use a type guard instead:
-```js
-try { something(); }
-catch (e) {
-  if (e instanceof Error){
-    // Here you go.
-  }
-}
-```
-
-## Interface `ElementClass` cannot simultaneously extend types `Component` and `Component`
-This happens when you have two `react.d.ts` (`@types/react/index.d.ts`) in the compilation context.
-
-**Fix**:
-* Delete `node_modules` and any `package-lock` (or yarn lock) and `npm install` again.
-* If it doesn't work, find the invalid module (all modules used by your project should have `react.d.ts` as a `peerDependency` and not a hard `dependency`) and report it on their project.
-
-
-## For search indexing
-You can ignore reading this. This section is for search engine indexing.
-
-> Other modules that people tend to use and get errors:
-* Cannot find name $
-* Cannot find module jquery
-
-[ambient]: ../types/ambient/d.ts.md
-[modules]: ../project/modules.md
+# Errors 
+In this section we discuss how to read and understand TypeScript errors. We follow this with common errors and their solutions.