FIX: need to be able to search replace within lines

(this is needed for very simple diffs and HTML)

Author: SamSaffron

lib/utils/diff_utils/simple_diff.rb

@@ -19,6 +19,9 @@ def apply(content, search, replace)
           raise ArgumentError, "content cannot be nil" if content.nil?
           raise ArgumentError, "search cannot be nil" if search.nil?
           raise ArgumentError, "replace cannot be nil" if replace.nil?
+          raise ArgumentError, "search cannot be empty" if search.empty?
+
+          return content.gsub(search, replace) if content.include?(search)
 
           lines = content.split("\n")
           search_lines = search.split("\n")

spec/lib/utils/diff_utils/simple_diff_spec.rb

@@ -121,6 +121,13 @@
       expect(subject.apply(content, search, replace)).to eq(expected.strip)
     end
 
+    it "handles partial line matches" do
+      content = "abc hello efg\nabc hello efg"
+      search = "hello"
+      replace = "bob"
+      expect(subject.apply(content, search, replace)).to eq("abc bob efg\nabc bob efg")
+    end
+
     it "handles JavaScript blocks in different orders" do
       content = <<~JS
         function first() {