Merge pull request #199 from polac24/add-graceful-missing-common-sha

Add support for graceful handling missing common sha

README.md

@@ -358,6 +358,7 @@ Note: This step is not required if at least one of these is true:
 | `disable_vfs_overlay` | A feature flag to disable virtual file system overlay support (temporary) | `false` | ⬜️ |
 | `custom_rewrite_envs` | A list of extra ENVs that should be used as placeholders in the dependency list. ENV rewrite process is optimistic - does nothing if an ENV is not defined in the pre/postbuild process. | `[]` | ⬜️ |
 | `irrelevant_dependencies_paths` | Regexes of files that should not be included in a list of dependencies. Warning! Add entries here with caution - excluding dependencies that are relevant might lead to a target overcaching. The regex can match either partially or fully the filepath, e.g. `\\.modulemap$` will exclude all `.modulemap` files. | `[]` | ⬜️ |
+| `gracefully_handle_missing_common_sha` | If true, do not fail `prepare` if cannot find the most recent common commits with the primary branch. That might be useful on CI, where a shallow clone is used and cloning depth is not big enough to fetch a commit from a primary branch | `false` | ⬜️ |
 
 ## Backend cache server
 

Sources/XCRemoteCache/Commands/Prepare/Prepare.swift

@@ -77,7 +77,18 @@ class Prepare: PrepareLogic {
             guard fileAccessor.fileExists(atPath: PhaseCacheModeController.xcodeSelectLink.path) else {
                 throw PrepareError.missingXcodeSelectDirectory
             }
-            let commonSha = try gitClient.getCommonPrimarySha()
+
+            let commonSha: String
+            do {
+                commonSha = try gitClient.getCommonPrimarySha()
+            } catch let GitClientError.noCommonShaWithPrimaryRepo(remoteName, error) {
+                guard context.gracefullyHandleMissingCommonSha else {
+                    throw GitClientError.noCommonShaWithPrimaryRepo(remoteName: remoteName, error: error)
+                }
+                infoLog("Cannot find a common sha with the primary branch: \(error). Gracefully disabling remote cache")
+                try disable()
+                return .failed
+            }
 
             if context.offline {
                 // Optimistically take first common sha

Sources/XCRemoteCache/Commands/Prepare/PrepareContext.swift

@@ -52,6 +52,8 @@ public struct PrepareContext {
     let cacheHealthPathProbeCount: Int
     /// clang wrapper output file
     let xcccCommand: URL
+    /// gracefully disable remote cache for missing common sha with the primary branch
+    let gracefullyHandleMissingCommonSha: Bool
 }
 
 extension PrepareContext {
@@ -77,5 +79,6 @@ extension PrepareContext {
         cacheAddresses = try config.cacheAddresses.map(URL.build)
         cacheHealthPath = config.cacheHealthPath
         cacheHealthPathProbeCount = config.cacheHealthPathProbeCount
+        gracefullyHandleMissingCommonSha = config.gracefullyHandleMissingCommonSha
     }
 }

Sources/XCRemoteCache/Config/XCRemoteCacheConfig.swift

@@ -148,6 +148,9 @@ public struct XCRemoteCacheConfig: Encodable {
     /// Note: The regex can match either partially or fully the filepath, e.g. `\\.modulemap$` will exclude
     /// all `.modulemap` files
     var irrelevantDependenciesPaths: [String] = []
+    /// If true, do not fail `prepare` if cannot find the most recent common commits with the primary branch
+    /// That might useful on CI, where a shallow clone is used
+    var gracefullyHandleMissingCommonSha: Bool = false
 }
 
 extension XCRemoteCacheConfig {
@@ -206,6 +209,8 @@ extension XCRemoteCacheConfig {
         merge.disableVFSOverlay = scheme.disableVFSOverlay ?? disableVFSOverlay
         merge.customRewriteEnvs = scheme.customRewriteEnvs ?? customRewriteEnvs
         merge.irrelevantDependenciesPaths = scheme.irrelevantDependenciesPaths ?? irrelevantDependenciesPaths
+        merge.gracefullyHandleMissingCommonSha =
+            scheme.gracefullyHandleMissingCommonSha ?? gracefullyHandleMissingCommonSha
         return merge
     }
 
@@ -273,6 +278,7 @@ struct ConfigFileScheme: Decodable {
     let disableVFSOverlay: Bool?
     let customRewriteEnvs: [String]?
     let irrelevantDependenciesPaths: [String]?
+    let gracefullyHandleMissingCommonSha: Bool?
 
     // Yams library doesn't support encoding strategy, see https://github.com/jpsim/Yams/issues/84
     enum CodingKeys: String, CodingKey {
@@ -323,6 +329,7 @@ struct ConfigFileScheme: Decodable {
         case disableVFSOverlay = "disable_vfs_overlay"
         case customRewriteEnvs = "custom_rewrite_envs"
         case irrelevantDependenciesPaths = "irrelevant_dependencies_paths"
+        case gracefullyHandleMissingCommonSha = "gracefully_handle_missing_common_sha"
     }
 }
 

Tests/XCRemoteCacheTests/Commands/PrepareTests.swift

@@ -89,4 +89,66 @@ class PrepareTests: XCTestCase {
 
         XCTAssertEqual(result, .preparedFor(sha: .init(sha: "2", age: 0), recommendedCacheAddress: remoteURL))
     }
+
+    func testFailsForMissingCommonShaWhenConfiguredToGrefullyDisable() throws {
+        git = GitClientFake(shaHistory: [], primaryBranchIndex: 0)
+        config.gracefullyHandleMissingCommonSha = true
+
+        let prepare = Prepare(
+            context: try PrepareContext(config, offline: false),
+            gitClient: git,
+            networkClients: [],
+            ccBuilder: CCWrapperBuilderFake(),
+            fileAccessor: FileManager.default,
+            globalCacheSwitcher: globalCacheSwitcher,
+            cacheInvalidator: CacheInvalidatorFake()
+        )
+
+        let result = try prepare.prepare()
+
+        XCTAssertEqual(result, .failed)
+    }
+
+    func testDisablesGlobalCacheForMissingCommonShaWhenConfiguredToGrefullyDisable() throws {
+        git = GitClientFake(shaHistory: [], primaryBranchIndex: 0)
+        config.gracefullyHandleMissingCommonSha = true
+        try globalCacheSwitcher.enable(sha: "starting_state")
+
+        let prepare = Prepare(
+            context: try PrepareContext(config, offline: false),
+            gitClient: git,
+            networkClients: [],
+            ccBuilder: CCWrapperBuilderFake(),
+            fileAccessor: FileManager.default,
+            globalCacheSwitcher: globalCacheSwitcher,
+            cacheInvalidator: CacheInvalidatorFake()
+        )
+
+        _ = try prepare.prepare()
+
+        XCTAssertEqual(globalCacheSwitcher.state, .disabled)
+    }
+
+    func testThrowsForMissingCommonSha() throws {
+        git = GitClientFake(shaHistory: [], primaryBranchIndex: 0)
+        config.gracefullyHandleMissingCommonSha = false
+
+        let prepare = Prepare(
+            context: try PrepareContext(config, offline: false),
+            gitClient: git,
+            networkClients: [],
+            ccBuilder: CCWrapperBuilderFake(),
+            fileAccessor: FileManager.default,
+            globalCacheSwitcher: globalCacheSwitcher,
+            cacheInvalidator: CacheInvalidatorFake()
+        )
+
+        XCTAssertThrowsError(try prepare.prepare()) { error in
+            switch error {
+            case GitClientError.noCommonShaWithPrimaryRepo: break
+            default:
+                XCTFail("Not expected error")
+            }
+        }
+    }
 }

Tests/XCRemoteCacheTests/TestDoubles/GitClientFake.swift

@@ -34,7 +34,10 @@ class GitClientFake: GitClient {
     }
 
     func getCommonPrimarySha() throws -> String {
-        shaHistory[primaryBranchIndex].sha
+        guard shaHistory.count > primaryBranchIndex else {
+            throw GitClientError.noCommonShaWithPrimaryRepo(remoteName: "testing", error: "SampleError")
+        }
+        return shaHistory[primaryBranchIndex].sha
     }
 
     func getShaDate(sha: String) throws -> Date {