linters.mdx (Under the Hood - Linters)

Summary: Restyle of page, including changes to spelling, grammar, links, and structure (where relevant).

Reviewed By: passy

Differential Revision: D36667953

fbshipit-source-id: 0ede69115f3652b00acf9658e472dba4bb8f799c
This commit is contained in:
Kevin Strider
2022-05-26 04:27:17 -07:00
committed by Facebook GitHub Bot
parent 15e9d105c4
commit 8f448dcfc8

View File

@@ -4,23 +4,21 @@ title: Linters
sidebar_label: Linters
---
Flipper Desktop comes with a variety of ESLint checks pre-enabled. This allows us
to enforce sustainable coding practices and skip over discussions in code reviews.
Flipper Desktop comes with a variety of ESLint checks pre-enabled. This enables us to enforce sustainable coding practices and skip over discussions in code reviews.
## Specific Linters
A short and incomplete list of unusual linters we deploy, why we do it and how to fix them.
This section contains an incomplete list of unusual linters we deploy, why we use them, and how to fix them (where relevant).
### `promise/no-nesting`
- **Summary:** Avoid nested then() or catch() statements. [More details.](https://github.com/xjamundx/eslint-plugin-promise/blob/development/docs/rules/no-nesting.md)
- **Why:** Nested promise chains can be difficult to read and reason about. Often, you can
achieve the same by either returning the promise and handling them on a higher level
or converting them to an async function.
- **Summary** - avoid nested then() or catch() statements. For more details, see [no-nesting.md](https://github.com/xjamundx/eslint-plugin-promise/blob/development/docs/rules/no-nesting.md) on GitHub.
- **Why** - nested promise chains can be difficult to read and understand. Often, you can achieve the same result by either returning the promise and handling them on a higher level or converting them to an async function.
**Example**
#### Example
*Before*
```js
private pushFileToiOSDevice(
udid: string,
@@ -67,18 +65,17 @@ async pushFileToiOSDevice(
}
```
In addition to less indentation, you also maintain the promise chain
here, meaning that you can handle potential errors on the call-side.
In addition to less indentation, you also maintain the promise chain here, meaning that you can handle potential errors on the call-side.
### `flipper/no-console-error-without-context`
- **Summary:** Avoid "Naked" console.error calls. Prefer `console.error("Failed to connect open iOS connection socket", e)` to `console.error(e)`.
- **Why:** We create error tasks internally for every `console.error` call. It can be hard
to find the origin of the error without context.
- **Summary** - avoid 'naked' console.error calls. Prefer `console.error("Failed to connect open iOS connection socket", e)` to `console.error(e)`.
- **Why** - we create error tasks internally for every `console.error` call. It can be hard to find the origin of the error without context.
**Example**
#### Example
*Before*
```js
try {
// ...
@@ -99,19 +96,13 @@ try {
### `promise/catch-or-return`
- **Summary:** Ensure that each time a `then()` is applied to a promise, a
`catch()` is applied as well. Exceptions are made if you are returning that
promise. [More
details.](https://github.com/xjamundx/eslint-plugin-promise/blob/development/docs/rules/catch-or-return.md)
- **Why:** Unhandled exceptions have no stack trace and will just show up as
"Unhandled promise rejection", making them very hard to triage and reproduce. By
always ensuring that promises are returned (ensuring they are a chain) or
explicitly catching errors, we can improve the user experience by acting more
quickly on errors.
- **Summary** - ensure that each time a `then()` is applied to a promise, a `catch()` is applied as well. Exceptions are made if you are returning that promise. For more details, see [catch-or-return.md](https://github.com/xjamundx/eslint-plugin-promise/blob/development/docs/rules/catch-or-return.md) on GitHub.
- **Why:** Unhandled exceptions have no stack trace and will just show up as "Unhandled promise rejection", making them very hard to triage and reproduce. By always ensuring that promises are returned (ensuring they are a chain) or explicitly catching errors, we can improve the user experience by acting more quickly on errors.
**Example**
#### Example
*Before*
```js
function request() {
// If fetch() fails, the exception will bubble to the top.
@@ -122,6 +113,7 @@ function request() {
```
*After*
```js
// Option 1
function request() {
@@ -143,12 +135,13 @@ function request() {
### `communist-spelling/communist-spelling`
- **Summary**: We try to avoid using British spellings for identifiers.
- **Why**: This is clearly controversial, but it's very inconvenient when you have to
bridge American and British APIs. `const greyColour = COLORS.GRAY;` is something
nobody should have to read or write.
- **Summary** - we try to avoid using British spellings for identifiers.
- **Why** - this is clearly controversial, but it's very inconvenient when you have to bridge American and British APIs. `const greyColour = COLORS.GRAY;` is something nobody should have to read or write.
#### Example
*Before*
```js
const GreyedOutOverlay = initialiseComponent();
```
@@ -161,12 +154,14 @@ const GrayedOutOverlay = initializeComponent();
### `no-restricted-properties`
- **Summary**: Why try to avoid using `electron.remote` directly.
- **Why**: Using [`electron.remote`](https://nornagon.medium.com/electrons-remote-module-considered-harmful-70d69500f31) is considered harmful.
Not only is accessing it slow, but it also makes it harder to abstract away from Electron which we're planning to do.
- **How to fix it**: For now, the best way is to use utilities whereever possible which cache the access. This is not always possible. Adding ignores for legitimate accesses is fine.
- **Summary** - try to avoid using `electron.remote` directly.
- **Why** - using [electron.remote](https://nornagon.medium.com/electrons-remote-module-considered-harmful-70d69500f31) is considered harmful. Not only is accessing it slow but it also makes it harder to abstract away from Electron, which we're planning to do.
- **How to fix it** - for now, the best way is to use utilities, wherever possible, which cache to access. This is not always possible. Adding ignores for legitimate accesses is fine.
#### Example
*Before*
```js
import electron from 'electron';
const portforwardingClient =
@@ -195,13 +190,12 @@ const portforwardingClient = getStaticPath(
### `node/no-sync`
- **Summary**: Use asynchronous methods whereever possible. [More details.](https://github.com/mysticatea/eslint-plugin-node/blob/master/docs/rules/no-sync.md)
- **Why**: Synchronous method calls block the event loop. Even innocous calls like `fs.existsSync()` can cause
frame drops for users or even long stalls.
- **How to fix it**: We have `fs-extra` as a dependency, which provides Promise-based alternatives for all `fs` functions.
Most often, replacing a sync call with an async call and adding an `await` is all that's needed.
- **Summary**: Use asynchronous methods wherever possible. [More details.](https://github.com/mysticatea/eslint-plugin-node/blob/master/docs/rules/no-sync.md)
- **Why**: Synchronous method calls block the event loop. Even innocuous calls like `fs.existsSync()` can cause frame drops for users or even long stalls.
- **How to fix it**: We have `fs-extra` as a dependency, which provides Promise-based alternatives for all `fs` functions. Most often, replacing a sync call with an async call and adding an `await` is all that's needed.
*Before*
```js
import fs from 'fs';
function ensureCertsExist() {