react-native run-ios can not find any simulator - ios

Question

I have been facing an issue where 'react-native run-ios' can not start, regardless of the simulator I add to the --simulator argument.
XCode has the correct location for the 'command line tools'
I am always getting the error:
Could not find iPhone X simulator
Error: Could not find iPhone X simulator
at resolve (/Users/eric/.../swim/node_modules/react-native/local-cli/runIOS/runIOS.js:149:13)
at new Promise (<anonymous>)
at runOnSimulator (/Users/eric/.../swim/node_modules/react-native/local-cli/runIOS/runIOS.js:134:10)
at Object.runIOS [as func] (/Users/eric/.../swim/node_modules/react-native/local-cli/runIOS/runIOS.js:106:12)
at Promise.resolve.then (/Users/eric/.../swim/node_modules/react-native/local-cli/cliEntry.js:117:22)
react-native info
> React Native Environment Info:
> System:
> OS: macOS 10.14.2
> CPU: (12) x64 Intel(R) Core(TM) i9-8950HK CPU # 2.90GHz
> Memory: 6.76 GB / 32.00 GB
> Shell: 3.2.57 - /bin/bash
> Binaries:
> Node: 10.15.0 - /usr/local/bin/node
> Yarn: 1.13.0 - /usr/local/bin/yarn
> npm: 6.4.1 - /usr/local/bin/npm
> SDKs:
> iOS SDK:
> Platforms: iOS 12.1, macOS 10.14, tvOS 12.1, watchOS 5.1
> IDEs:
> Android Studio: 3.1 AI-173.4819257
> Xcode: 10.1/10B61 - /usr/bin/xcodebuild
> npmPackages:
> react: 16.6.3 => 16.6.3
> react-native: 0.57.8 => 0.57.8
> npmGlobalPackages:
> create-react-native-app: 1.0.0
> react-native-cli: 2.0.1
> react-native-git-upgrade: 0.2.7

Answer 1

Update
It is fixed in v1.9.8.
Update cli is the easy solution
npm install -g react-native-cli#latest
This issue is fixed but not released yet.
https://github.com/react-native-community/react-native-cli/pull/274
So it can be solved temporarily to fix the file below.
/node_modules/react-native/local-cli/runIOS/findMatchingSimulator.js
Change this line
if (!version.startsWith('iOS') && !version.startsWith('tvOS')) {
to
if (!version.includes('iOS') && !version.includes('tvOS')) {
Do not forget apply this again when you reinstall packages.

Answer 2

I've found a temporary fix:
In the following file:
/node_modules/react-native/local-cli/runIOS/findMatchingSimulator.js
...change line 42 to:
if (!version.startsWith('com.apple.CoreSimulator.SimRuntime.iOS') && !version.startsWith('tvOS')) {

Answer 3

I tried like below
Open Xcode. Then Preferences -> Select Components in Tabs.
Then install any one(or more) of the available simulators on the list. Preferably the recent one at the top.
It solves the problem.

Answer 4

Try this script from Terminal
sed -i '' 's/startsWith/includes/g' node_modules/react-native/local-cli/runIOS/findMatchingSimulator.js
Now run
react-native run-ios

Answer 5

Just do
npm install
Then it will show warnings, then fix them by using following command
npm audit fix

Answer 6

Here is additional temporary fix too. I am using Catalina.
I this file:
/node_modules/react-native/local-cli/runIOS/findMatchingSimulator.js
Change line 42 to:
if (!version.includes('iOS') && !version.includes('tvOS')) {
Change line 52-53 from:
simulator.availability !== '(available)' &&
simulator.isAvailable !== 'YES'
to:
simulator.isAvailable !== true
because the returned json list from command xcrun simctl list --json devices, the property isAvailable is boolean and didn't have property 'availability'.

Answer 7

Just modify the findMatchingSimulator.js in node_modules/react-native/local-cli/runIOS/findMatchingSimulator.js.
First boot a Simulator then run xcrun simctl list --json devices and search the one with "state" : "Booted",.
Then add at the top in the findMatchingSimulator function:
return {
udid: <uuid from booted device>, // 'BFA2D7D0-AD49-472F-8279-585DDBBF9151'
name: <Name of the booted simulator>, //"iPhone X"
booted: true,
version: "com.apple.CoreSimulator.SimRuntime.iOS-13-1",
}

Answer 8

I solved it by replacing line number 62 in YourProjectFolder/node_modules/react-native/local-cli/runIOS/findMatchingSimulator.js
This line
if (
simulator.availability !== '(available)' &&
simulator.isAvailable !== 'YES'
) {
With this one
if (
!simulator.isAvailable
) {
In some case there may be some different solutions for everyone just debug findMatchingSimulator.js file by putting console.log() so you'll know why it is not detecting simulator. In my case the xcrun simctl list devices --json command not providing simulator.availability and simulator.isAvailable is not string it's bool.
I printed the simulator list which command is returning through the following line
console.log(JSON.stringify(simulator.simulatorName));
console.log(simulator.isAvailable);
console.log('-------------------------------------------------------------');
The after running command react-native run-ios --simulator="iPhone SE" I got output in the terminal and fixed code according to console print. And my simulator was running.

Answer 9

try npm install --force if you don't want to break your app with npm audit fix