From 174ffbb1533de8d462f529794540a93e2db16a12 Mon Sep 17 00:00:00 2001
From: Nathan Harris <nathan@mordil.info>
Date: Fri, 18 Sep 2020 23:17:53 -0700
Subject: [PATCH] Update metadata formatting for readability

Motivation:

For packages that generate logs and use them as part of the development process,
it is beneficial to be able to read through logs without having to write custom
log handlers or pull in a dependency for formatting only at dev time.

Modifications:

- Change: The format of `StreamLogHandler` to output metadata on newlines with tab indentation

Result:

Package authors will have an easier time debugging their applications without boilerplate code or dependencies.

This resolves #162
---
 Sources/Logging/Logging.swift        | 4 ++--
 Tests/LoggingTests/LoggingTest.swift | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Sources/Logging/Logging.swift b/Sources/Logging/Logging.swift
index 6014ccf1..c39cd04d 100644
--- a/Sources/Logging/Logging.swift
+++ b/Sources/Logging/Logging.swift
@@ -711,12 +711,12 @@ public struct StreamLogHandler: LogHandler {
             : self.prettify(self.metadata.merging(metadata!, uniquingKeysWith: { _, new in new }))
 
         var stream = self.stream
-        stream.write("\(self.timestamp()) \(level) \(self.label) :\(prettyMetadata.map { " \($0)" } ?? "") \(message)\n")
+        stream.write("\(self.timestamp()) \(level) \(self.label) : \(message)\n\(prettyMetadata.map { "\t\($0)\n" } ?? "\n")")
     }
 
     private func prettify(_ metadata: Logger.Metadata) -> String? {
         return !metadata.isEmpty
-            ? metadata.lazy.sorted(by: { $0.key < $1.key }).map { "\($0)=\($1)" }.joined(separator: " ")
+            ? metadata.lazy.sorted(by: { $0.key < $1.key }).map { "\($0)=\($1)" }.joined(separator: "\n\t")
             : nil
     }
 
diff --git a/Tests/LoggingTests/LoggingTest.swift b/Tests/LoggingTests/LoggingTest.swift
index dae41d3b..f357ff7a 100644
--- a/Tests/LoggingTests/LoggingTest.swift
+++ b/Tests/LoggingTests/LoggingTest.swift
@@ -629,9 +629,9 @@ class LoggingTest: XCTestCase {
         let testString = "my message is better than yours"
         log.critical("\(testString)", metadata: ["test": "test"])
 
-        let pattern = "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(\\+|-)\\d{4}\\s\(Logger.Level.critical)\\s\(label)\\s:\\stest=test\\s\(testString)$"
+        let pattern = "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(\\+|-)\\d{4}\\s\(Logger.Level.critical)\\s\(label)\\s:\\s\(testString)\\n\\stest=test\\n"
 
-        let messageSucceeded = interceptStream.interceptedText?.trimmingCharacters(in: .whitespacesAndNewlines).range(of: pattern, options: .regularExpression) != nil
+        let messageSucceeded = interceptStream.interceptedText?.trimmingCharacters(in: .whitespaces).range(of: pattern, options: .regularExpression) != nil
 
         XCTAssertTrue(messageSucceeded)
         XCTAssertEqual(interceptStream.strings.count, 1)
@@ -655,8 +655,8 @@ class LoggingTest: XCTestCase {
             return
         }
 
-        XCTAssert(interceptStream.strings[0].contains("a=a0 b=b0"))
-        XCTAssert(interceptStream.strings[1].contains("a=a1 b=b1"))
+        XCTAssert(interceptStream.strings[0].contains("a=a0\n\tb=b0"))
+        XCTAssert(interceptStream.strings[1].contains("a=a1\n\tb=b1"))
     }
 
     func testStdioOutputStreamFlush() {