Use NonDarwinLogger when running tests instead of os_log

'swift test' doesn't print os_log output to the command line. Use the  `NonDarwinLogger` that prints to stderr so we can view the log output in CI test runs.

Author: ahoppen

Package.swift

@@ -9,6 +9,12 @@ func hasEnvironmentVariable(_ name: String) -> Bool {
   return ProcessInfo.processInfo.environment[name] != nil
 }
 
+/// Use the `NonDarwinLogger` even if `os_log` can be imported.
+///
+/// This is useful when running tests using `swift test` because xctest will not display the output from `os_log` on the
+/// command line.
+let forceNonDarwinLogger = hasEnvironmentVariable("SOURCEKITLSP_FORCE_NON_DARWIN_LOGGER")
+
 // When building the toolchain on the CI, don't add the CI's runpath for the
 // final build before installing.
 let installAction = hasEnvironmentVariable("SOURCEKIT_LSP_CI_INSTALL")
@@ -19,11 +25,14 @@ let useLocalDependencies = hasEnvironmentVariable("SWIFTCI_USE_LOCAL_DEPS")
 
 // MARK: - Compute custom build settings
 
-let sourcekitLSPLinkSettings: [LinkerSetting]
+var sourcekitLSPLinkSettings: [LinkerSetting] = []
 if installAction {
-  sourcekitLSPLinkSettings = [.unsafeFlags(["-no-toolchain-stdlib-rpath"], .when(platforms: [.linux, .android]))]
-} else {
-  sourcekitLSPLinkSettings = []
+  sourcekitLSPLinkSettings += [.unsafeFlags(["-no-toolchain-stdlib-rpath"], .when(platforms: [.linux, .android]))]
+}
+
+var lspLoggingSwiftSettings: [SwiftSetting] = []
+if forceNonDarwinLogger {
+  lspLoggingSwiftSettings += [.define("SOURCEKITLSP_FORCE_NON_DARWIN_LOGGER")]
 }
 
 // MARK: - Build the package
@@ -135,7 +144,8 @@ let package = Package(
       dependencies: [
         .product(name: "Crypto", package: "swift-crypto")
       ],
-      exclude: ["CMakeLists.txt"]
+      exclude: ["CMakeLists.txt"],
+      swiftSettings: lspLoggingSwiftSettings
     ),
 
     .testTarget(

Sources/LSPLogging/Logging.swift

@@ -22,7 +22,7 @@ import Foundation
 /// The subsystem that should be used for any logging by default.
 public let subsystem = "org.swift.sourcekit-lsp"
 
-#if canImport(os)
+#if canImport(os) && !SOURCEKITLSP_FORCE_NON_DARWIN_LOGGER
 import os  // os_log
 
 public typealias LogLevel = os.OSLogType

Utilities/build-script-helper.py

@@ -202,6 +202,16 @@ def run_tests(swift_exec: str, args: argparse.Namespace) -> None:
     """
     swiftpm_args = get_swiftpm_options(swift_exec, args)
     additional_env = get_swiftpm_environment_variables(swift_exec, args)
+    # 'swift test' doesn't print os_log output to the command line. Use the 
+    # `NonDarwinLogger` that prints to stderr so we can view the log output in CI test 
+    # runs.
+    additional_env['SOURCEKITLSP_FORCE_NON_DARWIN_LOGGER'] = '1'
+
+    # CI doesn't contain any sensitive information. Log everything.
+    additional_env['SOURCEKITLSP_LOG_PRIVACY_LEVEL'] = 'sensitive'
+
+    # Log with the highest log level to simplify debugging of CI failures.
+    additional_env['SOURCEKITLSP_LOG_LEVEL'] = 'debug'
 
     bin_path = swiftpm_bin_path(swift_exec, swiftpm_args, additional_env=additional_env)
     tests = os.path.join(bin_path, 'sk-tests')