clear specific logs when using rake log:clear

2 files changed, 23 insertions, 4 deletions

diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index 4f18f4cdd2..5dbca2e9b4 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,5 +1,10 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Specify which logs to clear when using the `rake log:clear` task.
+    (e.g. rake log:clear LOGS=test,staging)
+
+    *Matt Bridges*
+
 *   Allow a `:dirs` key in the `SourceAnnotationExtractor.enumerate` options
     to explicitly set the directories to be traversed so it's easier to define
     custom rake tasks.
diff --git a/railties/lib/rails/tasks/log.rake b/railties/lib/rails/tasks/log.rake
index 6e1334692e..6c3f02eb0c 100644
--- a/railties/lib/rails/tasks/log.rake
+++ b/railties/lib/rails/tasks/log.rake
@@ -1,9 +1,23 @@
 namespace :log do
-  desc "Truncates all *.log files in log/ to zero bytes"
+  desc "Truncates all *.log files in log/ to zero bytes (specify which logs with LOGS=test,development)"
   task :clear do
-    FileList["log/*.log"].each do |log_file|
-      f = File.open(log_file, "w")
-      f.close
+    log_files.each do |file|
+      clear_log_file(file)
     end
   end
+
+  def log_files
+    if ENV['LOGS']
+      ENV['LOGS'].split(',')
+                  .map    { |file| "log/#{file.strip}.log" }
+                  .select { |file| File.exists?(file) }
+    else
+      FileList["log/*.log"]
+    end
+  end
+
+  def clear_log_file(file)
+    f = File.open(file, "w")
+    f.close
+  end
 end