How to create podspec file for a React Native Library - react-native

Question

I am writing my components in React Native using react-native cli and am damn frustrated and confused about configuring it to be consumed as a library. Here's how the react native folder structure looks like:
src
ios
build
projectName.xcodeproj
projectName.xcodeworkspace
PodFile
PodFile.lock
...
android
index.js
...
when I open the xcode and build the project everything works fine as expected, now here's the thing. My React Native code sits into a git repository (Repo-A) which is different from an ios-repository (Repo-B) which contains collection of lot of independent pods.
All I want is to configure my project (Repo-A) MyApp to be consumed by Repo-B. I want to understand two syntax:
How do I add podSpec file in my Repo-A so that it points to ios directory so that it could be picked up by other repositories (in this case Repo-B).
In order to include the podfile in a specific repo (Repo-B in this case), all I need to do is the below snippet or something else? [Also how does podFile get access to these private repositories?]
Here's how I would like to consume it:
pod 'MyApp', :git => 'https://github.com/<username>/my-app', :branch => 'main'
Someone please help me understanding how can I achieve this? (Connecting the podFiles).
Additionally, one more thing I would like to know is how the versioning works? Like lets say I make some updates to my codebase, if I push it all to main and rebuild the Repo-B would that be sufficient to update changes in app or should I be using tags and create podSpec for each changes?

Answer 1

I can answer at least part of your question:
In Repo-A, create a podspec file with the same name as your library: my-library-name.podspec. Add this code:
require "json"
package = JSON.parse(File.read(File.join(__dir__, "package.json")))
folly_version = '2021.06.28.00-v2'
folly_compiler_flags = '-DFOLLY_NO_CONFIG -DFOLLY_MOBILE=1 -DFOLLY_USE_LIBCPP=1 -Wno-comma -Wno-shorten-64-to-32'
Pod::Spec.new do |s|
s.name = "my-library-name"
s.version = package["version"]
s.summary = package["description"]
s.homepage = package["homepage"]
s.license = package["license"]
s.authors = package["author"]
s.platforms = { :ios => "10.0" }
s.source = { :git => "https://github.com/<username>/my-app", :tag => "#{s.version}" }
s.source_files = ['ios/']
s.dependency "React-Core"
# Don't install the dependencies when we run `pod install` in the old architecture.
if ENV['RCT_NEW_ARCH_ENABLED'] == '1' then
s.compiler_flags = folly_compiler_flags + " -DRCT_NEW_ARCH_ENABLED=1"
s.pod_target_xcconfig = {
"HEADER_SEARCH_PATHS" => "\"$(PODS_ROOT)/boost\"",
"CLANG_CXX_LANGUAGE_STANDARD" => "c++17"
}
s.dependency "React-Codegen"
s.dependency "RCT-Folly", folly_version
s.dependency "RCTRequired"
s.dependency "RCTTypeSafety"
s.dependency "ReactCommon/turbomodule/core"
end
end
The s.source_files points to the ios directory so that it can be referenced by other repositories.
Documentation on sourcing other repos in podspec: https://guides.cocoapods.org/syntax/podspec.html#source