Search back through renames [FCOM-4]

CHANGELOG.md

@@ -1,5 +1,5 @@
 ## Unreleased
-[no unreleased changes yet]
+- Search back through renames
 
 ## v0.10.0 (2024-06-28)
 - Enforce only major and minor parts of required Ruby version (loosening the

lib/fcom/querier.rb

@@ -5,6 +5,7 @@
 # This class executes a system command to retrieve the git history, which is passed through `rg`
 # (ripgrep), and then ultimately is fed back to `fcom` for parsing.
 class Fcom::Querier
+  prepend MemoWise
   include ::Fcom::OptionsHelpers
 
   def initialize(options)
@@ -13,6 +14,7 @@ def initialize(options)
 
   # rubocop:disable Metrics/CyclomaticComplexity
   # rubocop:disable Metrics/PerceivedComplexity
+  # rubocop:disable Metrics/MethodLength
   def query
     expression_to_match = search_string
     expression_to_match = Regexp.escape(expression_to_match).gsub('\\ ', ' ') unless regex_mode?
@@ -24,37 +26,88 @@ def query
 
     quote = expression_to_match.include?('"') ? "'" : '"'
 
-    command = <<~COMMAND.squish
-      git log
-        --format="commit %s|%H|%an|%cr (%ci)"
-        --patch
-        --full-diff
-        --no-textconv
-        #{%(--author="#{author}") if author}
-        #{"--since=#{days}.day" unless days.nil?}
-        --
-        #{path}
-        |
-
-      rg #{quote}(#{expression_to_match})|(^commit )|(^diff )#{quote}
-        --color never
-        #{'--ignore-case' if ignore_case?}
-        #{@options[:rg_options]}
-        |
-
-      #{'exe/' if development?}fcom #{quote}#{search_string}#{quote}
-        #{"--days #{days}" if days}
-        #{'--regex' if regex_mode?}
-        #{'--debug' if debug?}
-        #{'--ignore-case' if ignore_case?}
-        --path #{path}
-        --parse-mode
-        --repo #{repo}
-    COMMAND
-
-    Fcom.logger.debug("Executing command: #{command}")
-    system(command)
+    commands =
+      filename_by_most_recent_containing_commit.map do |commit, path_at_commit|
+        <<~COMMAND.squish
+          git log
+            --format="commit %s|%H|%an|%cr (%ci)"
+            --patch
+            --full-diff
+            --no-textconv
+            #{%(--author="#{author}") if author}
+            #{"--since=#{days}.day" unless days.nil?}
+            #{commit}
+            --
+            #{path_at_commit}
+            |
+
+          rg #{quote}(#{expression_to_match})|(^commit )|(^diff )#{quote}
+            --color never
+            #{'--ignore-case' if ignore_case?}
+            #{@options[:rg_options]}
+            |
+
+          #{'exe/' if development?}fcom #{quote}#{search_string}#{quote}
+            #{"--days #{days}" if days}
+            #{'--regex' if regex_mode?}
+            #{'--debug' if debug?}
+            #{'--ignore-case' if ignore_case?}
+            --path #{path_at_commit}
+            --parse-mode
+            --repo #{repo}
+        COMMAND
+      end
+
+    previous_command_generated_output = false
+
+    commands.each do |command|
+      Fcom.logger.debug("Executing command: #{command}")
+      output = `#{command}`
+
+      if output.empty?
+        previous_command_generated_output = false
+      else
+        if previous_command_generated_output
+          puts("\n\n") # print blank lines for spacing
+        end
+
+        previous_command_generated_output = true
+
+        puts(output)
+      end
+    end
   end
+  # rubocop:enable Metrics/MethodLength
   # rubocop:enable Metrics/PerceivedComplexity
   # rubocop:enable Metrics/CyclomaticComplexity
+
+  private
+
+  memo_wise \
+  def filename_by_most_recent_containing_commit
+    {
+      most_recent_commit_with_file => path,
+    }.merge(renames.transform_keys { "#{_1}^" })
+  end
+
+  memo_wise \
+  def most_recent_commit_with_file
+    if system(%(test -e "#{path}"))
+      'HEAD'
+    else
+      `git log --all -1 --format="%H" -- "#{path}"`.rstrip
+    end
+  end
+
+  memo_wise \
+  def renames
+    `git log HEAD --format=%H --name-status --follow --diff-filter=R -- '#{path}'`.
+      split(/\n(?=[0-9a-f]{40})/).
+      to_h do |sha_and_name_info|
+        sha_and_name_info.
+          match(/(?<sha>[0-9a-f]{40})\n\nR\d+\s+(?<previous_name>\S+)?/).
+          named_captures.
+          values_at('sha', 'previous_name')
+      end
+  end
 end

spec/fcom/querier_spec.rb

@@ -8,40 +8,58 @@
   describe '#query' do
     subject(:query) { querier.query }
 
-    it 'executes a #system call with the expected command' do
-      # rubocop:disable RSpec/AnyInstance
-      expect_any_instance_of(Kernel).
-        to receive(:system).
-        with(<<~COMMAND.squish)
-          git log --format="commit %s|%H|%an|%cr (%ci)" --patch --full-diff --no-textconv -- . |
-          rg "(the_search_string)|(^commit )|(^diff )" --color never |
-          fcom "the_search_string" --path . --parse-mode --repo testuser/testrepo
-        COMMAND
-      # rubocop:enable RSpec/AnyInstance
-
-      query
-    end
+    context 'when a system call indicates that the current directory exists' do
+      before do
+        expect(querier).
+          to receive(:system).
+          with('test -e "."').
+          and_return(true)
+      end
 
-    context 'when an author option is provided' do
-      let(:options) { stubbed_slop_options('the_search_string --author "David Runger"') }
+      context 'when there have been no file renames' do
+        before do
+          expect(querier).
+            to receive(:`).
+            with("git log HEAD --format=%H --name-status --follow --diff-filter=R -- '.'").
+            and_return('')
+        end
 
-      it 'executes a #system call with the expected command' do
-        # rubocop:disable RSpec/AnyInstance
-        expect_any_instance_of(Kernel).
-          to receive(:system).
-          with(<<~COMMAND.squish)
-            git log
-            --format="commit %s|%H|%an|%cr (%ci)"
-            --patch --full-diff --no-textconv
-            --author="David Runger"
-            -- .
-            |
-            rg "(the_search_string)|(^commit )|(^diff )" --color never |
-            fcom "the_search_string" --path . --parse-mode --repo testuser/testrepo
-          COMMAND
-        # rubocop:enable RSpec/AnyInstance
-
-        query
+        it 'executes a backticks system call with the expected command' do
+          expect(querier).
+            to receive(:`).
+            with(<<~COMMAND.squish).
+              git log --format="commit %s|%H|%an|%cr (%ci)" --patch --full-diff --no-textconv
+                HEAD -- . |
+              rg "(the_search_string)|(^commit )|(^diff )" --color never |
+              fcom "the_search_string" --path . --parse-mode --repo testuser/testrepo
+            COMMAND
+            and_return('')
+
+          query
+        end
+
+        context 'when an author option is provided' do
+          let(:options) { stubbed_slop_options('the_search_string --author "David Runger"') }
+
+          it 'executes a backticks system call with the expected command' do
+            expect(querier).
+              to receive(:`).
+              with(<<~COMMAND.squish).
+                git log
+                --format="commit %s|%H|%an|%cr (%ci)"
+                --patch --full-diff --no-textconv
+                --author="David Runger"
+                HEAD
+                -- .
+                |
+                rg "(the_search_string)|(^commit )|(^diff )" --color never |
+                fcom "the_search_string" --path . --parse-mode --repo testuser/testrepo
+              COMMAND
+              and_return('')
+
+            query
+          end
+        end
       end
     end
   end