Support explicit embedded resources and multi-env git

Author: linhay

Package.swift

@@ -25,16 +25,19 @@ let package = Package(
             ]),
         .target(
             name: "SwiftGitResourcesArm64",
+            dependencies: ["SwiftGit"],
             resources: [
                 .copy("Resource/git-instance.bundle")
             ]),
         .target(
             name: "SwiftGitResourcesX86_64",
+            dependencies: ["SwiftGit"],
             resources: [
                 .copy("Resource/git-instance.bundle")
             ]),
         .target(
             name: "SwiftGitResourcesUniversal",
+            dependencies: ["SwiftGit"],
             resources: [
                 .copy("Resource/git-instance.bundle")
             ]),

README.md

@@ -78,7 +78,7 @@ Important modules (quick code map)
   - Use `Git.data(...)` or `Git.run(...)` which delegate to `Shell.Instance`.
 
 - `GitEnvironment` (`Sources/SwiftGit/Custom/GitEnvironment.swift`)
-  - Selects between embedded git (`.embed`), system git (`.system`), or custom folder.
+  - Selects between embedded git (`.embed(...)`), system git (`.system`), or custom folder.
   - Exposes environment variables used to run git (e.g. `GIT_EXEC_PATH`).
 
 - `Git` (`Sources/SwiftGit/Custom/Git.swift`)
@@ -97,8 +97,18 @@ Embedded git bundle
   - `SwiftGitArm64` → `Sources/SwiftGitResourcesArm64/Resource/git-instance.bundle`
   - `SwiftGitX86_64` → `Sources/SwiftGitResourcesX86_64/Resource/git-instance.bundle`
   - `SwiftGitUniversal` → `Sources/SwiftGitResourcesUniversal/Resource/git-instance.bundle`
-- `SwiftGit` (base product) no longer embeds a bundle; `GitEnvironment.Style.embed` will only succeed if one of the resource products is linked.
-- `GitEnvironment.Style.auto` now maps to system git only; use `.embed` explicitly when you add a resource product.
+- `SwiftGit` (base product) no longer embeds a bundle; `.embed(.arm64/.x86_64/.universal)` works only when the corresponding resource product is linked.
+- `GitEnvironment.Style.auto` now maps to system git only; use `.embed(...)` explicitly when you add a resource product.
+
+Example usage (arm64):
+
+```swift
+import SwiftGit
+import SwiftGitResourcesArm64
+
+let env = try GitEnvironment(type: .embed(.arm64))
+let git = Git(environment: env)
+```
 - Agents and tests should not modify files under the bundles. Use `GitEnvironment.Style.custom(URL)` to point to an alternate git distribution.
 - To generate updated bundles, run `tools/update-git-bundle.sh` with the desired `--archs` and copy the result into the corresponding `Sources/SwiftGitResources*/Resource/` directory.
 - If a bundle looks unusually large, run `tools/fix-git-bundle-links.sh` to relink duplicate `git-*` binaries and shrink the footprint.
@@ -109,7 +119,7 @@ Tests and integration tests
 - Tests live under `Tests/SwiftGitTests/`.
   - Unit tests: parsing and helpers (safe parsing of `git` output, command splitting).
   - Integration tests: initialize temporary repos and run real git workflows (init, add, commit, tag, branch, stash, rebase, plumbing commands like `write-tree`).
-- Integration tests try to use the embedded git first and fall back to system git. If neither is available they skip.
+- Integration tests use system git; if git is unavailable they skip.
 - Helper examples: `Tests/SwiftGitTests/IntegrationTests.swift`, `PlumbingTests.swift`, `ShowCommitResultTests.swift`.
 
 Design & safety notes

Sources/SwiftGit/Custom/Git.swift

@@ -20,11 +20,20 @@ public class Git {
         }
     }
 
-    public let environment: GitEnvironment
+    public private(set) var environment: GitEnvironment
+    private let environments: [GitEnvironment]
+    private var activeEnvironment: GitEnvironment?
     public var shell = Shell.Instance()
 
     public init(environment: GitEnvironment) {
         self.environment = environment
+        self.environments = [environment]
+    }
+
+    public init(environments: [GitEnvironment]) {
+        precondition(!environments.isEmpty, "Git requires at least one GitEnvironment")
+        self.environments = environments
+        self.environment = environments[0]
     }
 
     private var cancellables = Set<AnyCancellable>()
@@ -35,23 +44,32 @@ extension Git {
     public func dataPublisher(_ commands: [String], context: Shell.Context? = nil)
         -> AnyPublisher<Data, Error>
     {
-        self.triggerOfBeforeRun(commands)
+        let env: GitEnvironment
+        do {
+            env = try resolveEnvironment()
+        } catch {
+            return Fail(error: error).eraseToAnyPublisher()
+        }
+        self.triggerOfBeforeRun(commands, environment: env)
         return
             shell
             .dataPublisher(
                 Shell.Arguments(
-                    exec: self.environment.resource.executableURL,
+                    exec: env.resource.executableURL,
                     commands: commands,
-                    context: self.deal(context: context))
+                    context: self.deal(context: context, environment: env))
             )
             .map({ [weak self] data in
                 guard let self = self else { return data }
-                self.triggerOfAfterRun(commands, data: data)
+                self.triggerOfAfterRun(commands, data: data, environment: env)
                 return data
             })
             .mapError({ [weak self] error in
                 guard let self = self else { return error }
-                _ = self.triggerOfAfterRun(commands, message: error.localizedDescription)
+                _ = self.triggerOfAfterRun(
+                    commands,
+                    message: error.localizedDescription,
+                    environment: env)
                 return error
             })
             .eraseToAnyPublisher()
@@ -124,18 +142,21 @@ extension Git {
     @discardableResult
     public func data(_ commands: [String], context: Shell.Context? = nil) async throws -> Data {
         do {
-            triggerOfBeforeRun(commands)
+            let env = try resolveEnvironment()
+            triggerOfBeforeRun(commands, environment: env)
             let data = try await shell.data(
                 .init(
-                    exec: environment.resource.executableURL,
+                    exec: env.resource.executableURL,
                     commands: commands,
-                    context: deal(context: context)))
-            triggerOfAfterRun(commands, data: data)
+                    context: deal(context: context, environment: env)))
+            triggerOfAfterRun(commands, data: data, environment: env)
             return data
         } catch GitError.processFatal(let message) {
-            throw triggerOfAfterRun(commands, message: message)
+            let env = try resolveEnvironment()
+            throw triggerOfAfterRun(commands, message: message, environment: env)
         } catch {
-            throw triggerOfAfterRun(commands, message: error.localizedDescription)
+            let env = try resolveEnvironment()
+            throw triggerOfAfterRun(commands, message: error.localizedDescription, environment: env)
         }
     }
 
@@ -166,28 +187,29 @@ extension Git {
         progress: @escaping @Sendable (GitProgress) -> GitProgressAction
     ) async throws -> String {
         try Task.checkCancellation()
-        triggerOfBeforeRun(commands)
+        let env = try resolveEnvironment()
+        triggerOfBeforeRun(commands, environment: env)
         let parser = GitProgressParser(progress: progress)
         do {
             let data = try await shell.data(
                 .init(
-                    exec: environment.resource.executableURL,
+                    exec: env.resource.executableURL,
                     commands: commands,
-                    context: deal(context: context)
+                    context: deal(context: context, environment: env)
                 ),
                 onStdout: { parser.handle($0) },
                 onStderr: { parser.handle($0) },
                 shouldCancel: { parser.isCancelRequested || Task.isCancelled }
             )
             parser.finish()
-            triggerOfAfterRun(commands, data: data)
+            triggerOfAfterRun(commands, data: data, environment: env)
             return String(data: data, encoding: .utf8)?.trimmingCharacters(in: .newlines) ?? ""
         } catch is CancellationError {
             throw CancellationError()
         } catch GitError.processFatal(let message) {
-            throw triggerOfAfterRun(commands, message: message)
+            throw triggerOfAfterRun(commands, message: message, environment: env)
         } catch {
-            throw triggerOfAfterRun(commands, message: error.localizedDescription)
+            throw triggerOfAfterRun(commands, message: error.localizedDescription, environment: env)
         }
     }
 
@@ -198,18 +220,21 @@ extension Git {
     @discardableResult
     public func data(_ commands: [String], context: Shell.Context? = nil) throws -> Data {
         do {
-            triggerOfBeforeRun(commands)
+            let env = try resolveEnvironment()
+            triggerOfBeforeRun(commands, environment: env)
             let data = try shell.data(
                 .init(
-                    exec: environment.resource.executableURL,
+                    exec: env.resource.executableURL,
                     commands: commands,
-                    context: deal(context: context)))
-            triggerOfAfterRun(commands, data: data)
+                    context: deal(context: context, environment: env)))
+            triggerOfAfterRun(commands, data: data, environment: env)
             return data
         } catch GitError.processFatal(let message) {
-            throw triggerOfAfterRun(commands, message: message)
+            let env = try resolveEnvironment()
+            throw triggerOfAfterRun(commands, message: message, environment: env)
         } catch {
-            throw triggerOfAfterRun(commands, message: error.localizedDescription)
+            let env = try resolveEnvironment()
+            throw triggerOfAfterRun(commands, message: error.localizedDescription, environment: env)
         }
     }
 
@@ -245,7 +270,7 @@ extension Git {
 
 extension Git {
 
-    fileprivate func deal(context: Shell.Context?) -> Shell.Context {
+    fileprivate func deal(context: Shell.Context?, environment: GitEnvironment) -> Shell.Context {
         var environmentDict = context?.environment ?? [:]
         environment.variables.forEach { item in
             environmentDict[item.key] = item.value
@@ -258,7 +283,11 @@ extension Git {
         return ctx
     }
 
-    fileprivate func triggerOfAfterRun(_ commands: [String], data: Data) {
+    fileprivate func triggerOfAfterRun(
+        _ commands: [String],
+        data: Data,
+        environment: GitEnvironment
+    ) {
         if let triggers = environment.triggersMap[.afterRun] {
             let content = GitTrigger.Content(commands: commands, data: data)
             triggers.forEach({ item in
@@ -267,15 +296,19 @@ extension Git {
         }
     }
 
-    fileprivate func triggerOfAfterRun(_ commands: [String], message: String) -> GitError {
+    fileprivate func triggerOfAfterRun(
+        _ commands: [String],
+        message: String,
+        environment: GitEnvironment
+    ) -> GitError {
         let error = GitTrigger.Error(commands: commands, message: message)
         environment.triggersMap[.afterRun]?.forEach({ item in
             item.action(.failure(error))
         })
         return GitError.processFatal(error.message)
     }
 
-    fileprivate func triggerOfBeforeRun(_ commands: [String]) {
+    fileprivate func triggerOfBeforeRun(_ commands: [String], environment: GitEnvironment) {
         if let triggers = environment.triggersMap[.beforeRun] {
             let content = GitTrigger.Content(commands: commands, data: Data())
             triggers.forEach({ item in
@@ -285,3 +318,32 @@ extension Git {
     }
 
 }
+
+extension Git {
+
+    private func resolveEnvironment() throws -> GitEnvironment {
+        if let active = activeEnvironment {
+            return active
+        }
+        for env in environments {
+            if isUsable(env) {
+                activeEnvironment = env
+                environment = env
+                return env
+            }
+        }
+        throw GitError.noGitInstanceFoundOnSystem
+    }
+
+    private func isUsable(_ env: GitEnvironment) -> Bool {
+        let execPath = env.resource.executableURL.path
+        guard FileManager.default.isExecutableFile(atPath: execPath) else {
+            return false
+        }
+        if let execPath = env.resource.envExecPath {
+            return FileManager.default.fileExists(atPath: execPath)
+        }
+        return true
+    }
+
+}

Sources/SwiftGit/Custom/GitEnvironment.swift

@@ -51,7 +51,7 @@ extension GitEnvironment {
     }
 
     public enum Style {
-        case embed
+        case embed(EmbeddedResource)
         case system
         case custom(_ url: URL)
         case auto
@@ -64,12 +64,13 @@ extension GitEnvironment {
         triggers: [GitTrigger] = []
     ) throws {
         switch type {
-        case .embed:
+        case .embed(let embedded):
             guard
-                let resourceBundle = Self.findEmbeddedResourceBundle(),
-                let embeddedURL = resourceBundle.url(forResource: "git-instance", withExtension: "bundle"),
-                let bundle = Bundle(url: embeddedURL),
-                let resource = Resource(bundle: bundle)
+                let embeddedURL = embedded.bundle.url(
+                    forResource: "git-instance",
+                    withExtension: "bundle"),
+                let resourceBundle = Bundle(url: embeddedURL),
+                let resource = Resource(bundle: resourceBundle)
             else {
                 throw GitError.unableLoadEmbeddGitInstance
             }
@@ -112,42 +113,12 @@ extension GitEnvironment {
 
 extension GitEnvironment {
 
-    private static func findEmbeddedResourceBundle() -> Bundle? {
-        let candidates: [String]
-#if arch(arm64)
-        candidates = [
-            "SwiftGitResourcesArm64",
-            "SwiftGitResourcesUniversal",
-            "SwiftGitResourcesX86_64",
-            "SwiftGit"
-        ]
-#elseif arch(x86_64)
-        candidates = [
-            "SwiftGitResourcesX86_64",
-            "SwiftGitResourcesUniversal",
-            "SwiftGitResourcesArm64",
-            "SwiftGit"
-        ]
-#else
-        candidates = [
-            "SwiftGitResourcesUniversal",
-            "SwiftGitResourcesArm64",
-            "SwiftGitResourcesX86_64",
-            "SwiftGit"
-        ]
-#endif
-
-        let bundles = Bundle.allBundles + Bundle.allFrameworks
-        for name in candidates {
-            if let url = Bundle.main.url(forResource: name, withExtension: "bundle"),
-               let bundle = Bundle(url: url) {
-                return bundle
-            }
-            if let bundle = bundles.first(where: { $0.bundleURL.lastPathComponent == "\(name).bundle" }) {
-                return bundle
-            }
+    public struct EmbeddedResource {
+        public let bundle: Bundle
+
+        public init(bundle: Bundle) {
+            self.bundle = bundle
         }
-        return nil
     }
 
     public struct Resource {

Sources/SwiftGitResourcesArm64/SwiftGitResourcesArm64.swift

@@ -1,5 +1,12 @@
 import Foundation
+import SwiftGit
 
 public enum SwiftGitResourcesArm64 {
     public static let bundle = Bundle.module
 }
+
+public extension GitEnvironment.EmbeddedResource {
+    static var arm64: GitEnvironment.EmbeddedResource {
+        GitEnvironment.EmbeddedResource(bundle: SwiftGitResourcesArm64.bundle)
+    }
+}

Sources/SwiftGitResourcesUniversal/SwiftGitResourcesUniversal.swift

@@ -1,5 +1,12 @@
 import Foundation
+import SwiftGit
 
 public enum SwiftGitResourcesUniversal {
     public static let bundle = Bundle.module
 }
+
+public extension GitEnvironment.EmbeddedResource {
+    static var universal: GitEnvironment.EmbeddedResource {
+        GitEnvironment.EmbeddedResource(bundle: SwiftGitResourcesUniversal.bundle)
+    }
+}