Add a function that wraps output in an md fence

2 files changed, 154 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 54e7dcd..296f4f4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,5 @@
 pub mod logger;
+pub mod md_fence_wrapper;
 pub mod normalizer;
 pub mod renderer;
 pub mod run;
diff --git a/src/md_fence_wrapper.rs b/src/md_fence_wrapper.rs
new file mode 100644
index 0000000..2928efa
--- /dev/null
+++ b/src/md_fence_wrapper.rs
@@ -0,0 +1,153 @@
+use std::{
+    io::{Read, Write},
+    path::Path,
+};
+
+use crate::{logger::Logger, run::run, util::fence::generate_outer_backticks};
+
+pub fn wrap_in_md_fence<R: Read, W: Write>(
+    input: R,
+    mut output: W,
+    root: &Path,
+    origin_base: &Path,
+    project_title: Option<&str>,
+    logger: Logger,
+) -> Result<(), Box<dyn std::error::Error>> {
+    let mut md_output = Vec::new();
+    run(
+        input,
+        &mut md_output,
+        root,
+        origin_base,
+        project_title,
+        logger,
+    )?;
+    let fence = generate_outer_backticks(&md_output);
+    writeln!(output, "{}markdown", fence)?;
+    output.write_all(&md_output)?;
+    writeln!(output, "{}", fence)?;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use std::fs;
+    use std::io::{Cursor, Read, Write};
+    use tempfile::tempdir;
+
+    use crate::logger::Logger;
+
+    use super::wrap_in_md_fence;
+
+    fn wrap_with_default_logger<R: Read, W: Write>(
+        input: R,
+        output: W,
+        root: &std::path::Path,
+        origin_base: &std::path::Path,
+        project_title: Option<&str>,
+    ) -> Result<(), Box<dyn std::error::Error>> {
+        let logger = Logger::default();
+        wrap_in_md_fence(input, output, root, origin_base, project_title, logger)
+    }
+
+    #[test]
+    fn empty_input_produces_wrapped_header() {
+        let temp_dir = tempdir().unwrap();
+        let input = Cursor::new(b"");
+        let mut output = Vec::new();
+        let root = temp_dir.path();
+        let origin_base = temp_dir.path();
+
+        wrap_with_default_logger(input, &mut output, root, origin_base, Some("Project name"))
+            .unwrap();
+
+        assert_eq!(
+            String::from_utf8(output).unwrap(),
+            "```markdown\n# Project name\n```\n"
+        );
+    }
+
+    #[test]
+    fn single_file_is_wrapped() {
+        let temp_dir = tempdir().unwrap();
+        let origin_base = temp_dir.path();
+        let input = Cursor::new(b"test_main.rs\0");
+        let mut output = Vec::new();
+        let root = temp_dir.path();
+
+        fs::write(origin_base.join("test_main.rs"), "fn main() {}").unwrap();
+
+        wrap_with_default_logger(input, &mut output, root, origin_base, None).unwrap();
+
+        let output_str = String::from_utf8(output).unwrap();
+        // Must contain outer fence
+        assert!(output_str.starts_with("````markdown\n"));
+        assert!(output_str.ends_with("\n````\n"));
+        // Must contain file content
+        assert!(output_str.contains("## File: test_main.rs"));
+        assert!(output_str.contains("fn main() {}"));
+    }
+
+    #[test]
+    fn multiple_files_are_enveloped_using_only_one_outer_fence_while_each_having_its_own_fence() {
+        let temp_dir = tempdir().unwrap();
+        let origin_base = temp_dir.path();
+        let input = Cursor::new(b"a.rs\0b.rs\0");
+        let mut output = Vec::new();
+        let root = temp_dir.path();
+
+        fs::write(origin_base.join("a.rs"), "A").unwrap();
+        fs::write(origin_base.join("b.rs"), "B").unwrap();
+
+        wrap_with_default_logger(input, &mut output, root, origin_base, None).unwrap();
+
+        let output_str = String::from_utf8(output).unwrap();
+        // Each inner file must have its own language‑specific fence
+        assert!(output_str.contains("```rust\nA\n```"));
+        assert!(output_str.contains("```rust\nB\n```"));
+        // Only one outer fence at start and end
+        assert_eq!(output_str.matches("````markdown").count(), 1);
+        assert_eq!(output_str.matches("\n````\n").count(), 1);
+    }
+
+    #[test]
+    fn inner_file_with_four_backticks_causes_outer_fence_of_six_backticks() {
+        let temp_dir = tempdir().unwrap();
+        let origin_base = temp_dir.path();
+        let input = Cursor::new(b"backticks.rs\0");
+        let mut output = Vec::new();
+        let root = temp_dir.path();
+
+        let content = "````"; // 4 backticks
+        fs::write(origin_base.join("backticks.rs"), content).unwrap();
+
+        wrap_with_default_logger(input, &mut output, root, origin_base, None).unwrap();
+
+        let output_str = String::from_utf8(output).unwrap();
+        // Inner fence should be 5 backticks because inner content contains 4 backticks
+        assert!(output_str.contains("`````rust\n````\n`````"));
+        // Outer fence must then be 6 backticks
+        assert!(output_str.starts_with("``````markdown\n"));
+        assert!(output_str.ends_with("\n``````\n"));
+    }
+
+    #[test]
+    fn project_title_with_three_backticks_causes_outer_fence_of_four_backticks() {
+        let temp_dir = tempdir().unwrap();
+        let input = Cursor::new(b"");
+        let mut output = Vec::new();
+        let root = temp_dir.path();
+        let origin_base = temp_dir.path();
+
+        let project_title = "Project ``` name";
+        wrap_with_default_logger(input, &mut output, root, origin_base, Some(project_title))
+            .unwrap();
+
+        let output_str = String::from_utf8(output).unwrap();
+        // Outer fence must be 4 backticks because the header contains 3 backticks
+        assert!(output_str.starts_with("````markdown\n"));
+        assert!(output_str.ends_with("\n````\n"));
+        // The header line itself should appear unchanged
+        assert!(output_str.contains("# Project ``` name"));
+    }
+}