Make file style to be colored with same structure while color_only #405 (#436)

* Add config property of color_only

* Delete force assign raw to file_style when color_only

* Print filemeta in color with rawline when color_only mode

* Cargo fmt

* Add test if file_style with color_only has style

* Add comment about color_only

4 files changed, 38 insertions, 6 deletions

diff --git a/src/config.rs b/src/config.rs
index a8718c51..b2cd2eab 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -21,6 +21,7 @@ pub struct Config {
     pub available_terminal_width: usize,
     pub background_color_extends_to_terminal_width: bool,
     pub commit_style: Style,
+    pub color_only: bool,
     pub decorations_width: cli::Width,
     pub file_added_label: String,
     pub file_copied_label: String,
@@ -150,6 +151,7 @@ impl From<cli::Opt> for Config {
                 .computed
                 .background_color_extends_to_terminal_width,
             commit_style,
+            color_only: opt.color_only,
             decorations_width: opt.computed.decorations_width,
             file_added_label: opt.file_added_label,
             file_copied_label: opt.file_copied_label,
diff --git a/src/delta.rs b/src/delta.rs
index 94b72650..d7724802 100644
--- a/src/delta.rs
+++ b/src/delta.rs
@@ -115,6 +115,10 @@ where
                     &minus_file,
                 ));
             }
+            if config.color_only {
+                handle_generic_file_meta_header_line(&mut painter, &line, &raw_line, config)?;
+                continue;
+            }
         } else if (state == State::FileMeta || source == Source::DiffUnified)
             && (line.starts_with("+++ ")
                 || line.starts_with("rename to ")
@@ -127,6 +131,10 @@ where
                 &plus_file,
             ));
             current_file_pair = Some((minus_file.clone(), plus_file.clone()));
+            if config.color_only {
+                handle_generic_file_meta_header_line(&mut painter, &line, &raw_line, config)?;
+                continue;
+            }
             if should_handle(&State::FileMeta, config)
                 && handled_file_meta_header_line_file_pair != current_file_pair
             {
@@ -181,7 +189,8 @@ where
             continue;
         }
 
-        if state == State::FileMeta && should_handle(&State::FileMeta, config) {
+        if state == State::FileMeta && should_handle(&State::FileMeta, config) && !config.color_only
+        {
             // The file metadata section is 4 lines. Skip them under non-plain file-styles.
             continue;
         } else {
@@ -318,7 +327,8 @@ fn handle_generic_file_meta_header_line(
     raw_line: &str,
     config: &Config,
 ) -> std::io::Result<()> {
-    if config.file_style.is_omitted {
+    // FIXME: this may be able to be refactored by moving to should_handle.
+    if config.file_style.is_omitted && !config.color_only {
         return Ok(());
     }
     let decoration_ansi_term_style;
@@ -361,7 +371,9 @@ fn handle_generic_file_meta_header_line(
             draw::write_no_decoration
         }
     };
-    writeln!(painter.writer)?;
+    if !config.color_only {
+        writeln!(painter.writer)?;
+    }
     draw_fn(
         painter.writer,
         &format!("{}{}", line, if pad { " " } else { "" }),
diff --git a/src/options/set.rs b/src/options/set.rs
index 1fc8b4d2..eda89add 100644
--- a/src/options/set.rs
+++ b/src/options/set.rs
@@ -190,13 +190,13 @@ pub fn set_options(
         compute_line_numbers_mode(opt, &builtin_features, git_config, &option_names);
     opt.computed.paging_mode = parse_paging_mode(&opt.paging_mode);
 
-    // --color-only is used for interactive.diffFilter (git add -p) and side-by-side cannot be used
-    // there (does not emit lines in 1-1 correspondence with raw git output). See #274.
+    // --color-only is used for interactive.diffFilter (git add -p). side-by-side, and
+    // **-decoration-style cannot be used there (does not emit lines in 1-1 correspondence with raw git output).
+    // See #274.
     if opt.color_only {
         opt.side_by_side = false;
         opt.file_decoration_style = "none".to_string();
         opt.commit_decoration_style = "none".to_string();
-        opt.file_style = "raw".to_string();
         opt.commit_style = "raw".to_string();
         opt.hunk_header_style = "raw".to_string();
         opt.hunk_header_decoration_style = "none".to_string();
diff --git a/src/tests/test_example_diffs.rs b/src/tests/test_example_diffs.rs
index 6668acce..e9a265de 100644
--- a/src/tests/test_example_diffs.rs
+++ b/src/tests/test_example_diffs.rs
@@ -972,6 +972,24 @@ src/align.rs
     }
 
     #[test]
+    // TODO: commit-style and hunk-header-style are required to add.
+    fn test_file_style_with_color_only_has_style() {
+        let config =
+            integration_test_utils::make_config_from_args(&["--color-only", "--file-style", "red"]);
+        let output = integration_test_utils::run_delta(GIT_DIFF_SINGLE_HUNK, &config);
+
+        ansi_test_utils::assert_line_has_style(&output, 8, "--- a/src/align.rs", "red", &config);
+        ansi_test_utils::assert_line_has_style(&output, 9, "+++ b/src/align.rs", "red", &config);
+        let output = strip_ansi_codes(&output);
+        assert!(output.contains(
+            "\
+--- a/src/align.rs
++++ b/src/align.rs
+"
+        ));
+    }
+
+    #[test]
     fn test_hunk_header_style_colored_input_color_is_stripped_under_normal() {
         let config = integration_test_utils::make_config_from_args(&[
             "--hunk-header-style",