How to locally test Swift Package Manager components on Focus iOS

This is a guide on testing the Swift Package Manager component locally against a local build of Focus iOS. For more information on our Swift Package Manager design, read the ADR that introduced it

NOTE - This guide is slightly out of date and needs to be updated. Better instructions can be found in the instructions for Firefox, but that process needs some Focus-specific tweaks.

This guide assumes the component you want to test is already distributed with the rust-components-swift repository, you can read the guide for adding a new component if you would like to distribute a new component.

To test a component locally, you will need to do the following:

1. Build an xcframework in a local checkout of application-services
2. Include the xcframework in a local checkout of rust-components-swift
3. Run the make-tag script in rust-components-swift using a local checkout of application-services
4. Include the local checkout of rust-components-swift in Focus

Below are more detailed instructions for each step

Building the xcframework

To build the xcframework do the following:

1. In a local checkout of application-services, navigate to megazords/ios-rust/
2. Run the build-xcframework.sh script:

$ ./build-xcframework.sh --focus

This will produce a file name FocusRustComponents.xcframework.zip in the focus directory that contains the following, built for all our target iOS platforms.

• The compiled Rust code for all the crates listed in Cargo.toml as a static library
• The C header files and Swift module maps for the components

Include the xcframework in a local checkout of rust-components-swift

After you generated the FocusRustComponents.xcframework.zip in the previous step, do the following to include it in a local checkout of rust-components-swift:

1. clone a local checkout of rust-components-swift, not inside the application-services repository:

   git clone https://github.com/mozilla/rust-components.swift.git
   

2. Unzip the FocusRustComponents.xcframework.zip into the rust-components-swift repository: (Assuming you are in the root of the rust-components-swift directory and application-services is a neighbor directory)

    unzip -o ../application-services/megazords/ios-rust/focus/FocusRustComponents.xcframework.zip -d .
   

3. Change the Package.swift’s reference to the xcframework to point to the unzipped FocusRustComponents.xcframework that was created in the previous step. You can do this by uncommenting the following line:

       path: "./FocusRustComponents.xcframework"
   

   and commenting out the following lines:

       url: focusUrl,
       checksum: focusChecksum,
   

Run the generation script with a local checkout of application services

For this step, run the following script from inside the rust-components-swift repository (assuming that application-services is a neighboring directory to rust-components-swift).

./generate.sh ../application-services

Once that is done, stage and commit the changes the script ran. Xcode can only pick up committed changes.

Include the local checkout of rust-components-swift in Focus

This is the final step to include your local changes into Focus. Do the following steps:

1. Clone a local checkout of Focus if you haven’t already. Make sure you also install the project dependencies, more information in their build instructions

2. Open Blockzilla.xcodeproj in Xcode

3. Navigate to the Swift Packages in Xcode:

4. Remove the dependency on rust-components-swift as listed on Xcode, you can click the dependency then click the -

5. Add a new swift package by clicking the +:

   1. On the top right, enter the full path to your rust-components-swift checkout, preceded by file://. If you don’t know what that is, run pwd in while in rust-components-swift. For example: file:///Users/tarikeshaq/code/rust-components-swift
   2. Change the branch to be the checked-out branch of rust-component-swift you have locally. This is what the dialog should look like:
   3. Click Add Package
   4. Now include the FocusAppServices library.

   Note: If Xcode prevents you from adding the dependency to reference a local package, you will need to manually modify the Blockzilla.xcodeproj/project.pbxproj and replace every occurrence of https://github.com/mozilla/rust-components-swift with the full path to your local checkout.

6. Finally, attempt to build focus, and if all goes well it should launch with your code. If you face any problems, feel free to contact us