diff --git a/Dangerfile b/Dangerfile
index 6dbf4a1..cd6692d 100644
--- a/Dangerfile
+++ b/Dangerfile
@@ -1,7 +1,20 @@
-message("Hello, this worked")
-
-# including in a project's CHANGELOG for example
-declared_trivial = github.pr_title.include? "#trivial"
-
 # Make it more obvious that a PR is a work in progress and shouldn't be merged yet
 warn("PR is classed as Work in Progress") if github.pr_title.include? "[WIP]"
+
+fail "Please provide a summary in the Pull Request description" if github.pr_body.length < 5
+
+warn "#{github.html_link("Package.swift")} was edited." if git.modified_files.include? "Package.swift"
+warn "#{github.html_link("Makefile")} was edited." if git.modified_files.include? "Makefile"
+
+# Check if tests were written for swift files
+def isTest?(file)
+  file.end_with? "_TestCase.swift"
+end
+
+files = (git.added_files + git.modified_files).select{ |file| isTest?(file) }
+tests = (git.added_files + git.modified_files).select{ |file| !isTest?(file) }
+
+files.each do |file|
+	next if tests.any? { |e| e.contains? file }
+	fail("Please add a test case for #{file}.")
+end
diff --git a/Sources/Parsel/Temp.swift b/Sources/Parsel/Temp.swift
new file mode 100644
index 0000000..e69de29