[refactor] extract and centralize output writing logic into write_outputs function in output.rs for improved code reuse and maintainability

src/output.rs

@@ -0,0 +1,89 @@
+use std::fs::File;
+use std::io::Write;
+use std::path::Path;
+
+use anyhow::Context;
+
+use crate::render_srt;
+use crate::OutputRoot;
+
+/// Which formats to write.
+pub struct OutputFormats {
+    pub json: bool,
+    pub toml: bool,
+    pub srt: bool,
+}
+
+impl OutputFormats {
+    pub fn all() -> Self {
+        Self { json: true, toml: true, srt: true }
+    }
+}
+
+/// Write outputs for the given base path (without extension).
+/// This will create files named `base.json`, `base.toml`, and `base.srt`
+/// according to the `formats` flags. JSON and TOML will always end with a trailing newline.
+pub fn write_outputs(base: &Path, root: &OutputRoot, formats: &OutputFormats) -> anyhow::Result<()> {
+    if formats.json {
+        let json_path = base.with_extension("json");
+        let mut json_file = File::create(&json_path).with_context(|| {
+            format!("Failed to create output file: {}", json_path.display())
+        })?;
+        serde_json::to_writer_pretty(&mut json_file, root)?;
+        // ensure trailing newline
+        writeln!(&mut json_file)?;
+    }
+
+    if formats.toml {
+        let toml_path = base.with_extension("toml");
+        let toml_str = toml::to_string_pretty(root)?;
+        let mut toml_file = File::create(&toml_path).with_context(|| {
+            format!("Failed to create output file: {}", toml_path.display())
+        })?;
+        toml_file.write_all(toml_str.as_bytes())?;
+        if !toml_str.ends_with('\n') {
+            writeln!(&mut toml_file)?;
+        }
+    }
+
+    if formats.srt {
+        let srt_path = base.with_extension("srt");
+        let srt_str = render_srt(&root.items);
+        let mut srt_file = File::create(&srt_path).with_context(|| {
+            format!("Failed to create output file: {}", srt_path.display())
+        })?;
+        srt_file.write_all(srt_str.as_bytes())?;
+    }
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::OutputEntry;
+
+    #[test]
+    fn write_outputs_creates_files_and_newlines() {
+        let dir = tempfile::tempdir().unwrap();
+        let base = dir.path().join("test_base");
+        let items = vec![OutputEntry { id: 0, speaker: "Alice".to_string(), start: 0.0, end: 1.23, text: "Hello".to_string() }];
+        let root = OutputRoot { items };
+
+        write_outputs(&base, &root, &OutputFormats::all()).unwrap();
+
+        let json_path = base.with_extension("json");
+        let toml_path = base.with_extension("toml");
+        let srt_path = base.with_extension("srt");
+
+        assert!(json_path.exists(), "json file should exist");
+        assert!(toml_path.exists(), "toml file should exist");
+        assert!(srt_path.exists(), "srt file should exist");
+
+        let json = std::fs::read_to_string(&json_path).unwrap();
+        let toml = std::fs::read_to_string(&toml_path).unwrap();
+
+        assert!(json.ends_with('\n'), "json should end with newline");
+        assert!(toml.ends_with('\n'), "toml should end with newline");
+    }
+}