don't require existing override

src/lib.rs

@@ -1,4 +1,4 @@
-use std::sync::{Arc, LazyLock};
+use std::sync::Arc;
 
 pub(crate) mod prelude {
     #![allow(unused_imports)]
@@ -25,6 +25,8 @@ pub(crate) mod prelude {
     pub use fs_err::File;
     #[cfg(unix)]
     pub use fs_err::os::unix::fs::{FileExt, OpenOptionsExt};
+
+    pub use tap::{Pipe, Tap};
 }
 
 use prelude::*;
@@ -48,20 +50,21 @@ pub const ASCII_WHITESPACE: &[char] = &['\t', '\n', '\x0C', '\r', ' '];
 #[derive(Debug, Clone, PartialEq, Hash, Serialize, Deserialize)]
 pub struct DefinitionWithLocation {
     pub file: Box<Path>,
-    pub value: Box<str>,
+    pub value: Box<serde_json::Value>,
 }
 
-pub fn get_where(option_name: &str, configuration_nix: &Path) -> Result<Box<Path>, BoxDynError> {
-    let expr: OsString = [
-        // foo
+pub fn expr_for_configuration(source_file: &Path) -> OsString {
+    [
         OsStr::new("import <nixpkgs/nixos> { configuration = "),
-        configuration_nix.as_os_str(),
+        source_file.as_os_str(),
         OsStr::new("; }"),
     ]
     .into_iter()
-    .map(ToOwned::to_owned)
-    .collect();
+    .collect()
+}
 
+pub fn get_where(option_name: &str, configuration_nix: &Path) -> Result<Box<Path>, BoxDynError> {
+    let expr = expr_for_configuration(configuration_nix);
     let attrpath = format!("options.{}.definitionsWithLocations", option_name);
 
     let output = nixcmd::NixEvalExpr { expr, attrpath }
@@ -75,19 +78,10 @@ pub fn get_where(option_name: &str, configuration_nix: &Path) -> Result<Box<Path
     Ok(Box::from(last_location.file))
 }
 
-pub fn get_highest_prio(
-    option_name: &str,
-    source: SourceFile,
-) -> Result<(i64, SourceLine), BoxDynError> {
+pub fn get_highest_prio(option_name: &str, source: SourceFile) -> Result<i64, BoxDynError> {
     // Get the current highest priority.
 
-    let expr: OsString = [
-        OsStr::new("import <nixpkgs/nixos> { configuration = "),
-        source.path().as_os_str(),
-        OsStr::new("; }"),
-    ]
-    .into_iter()
-    .collect();
+    let expr = expr_for_configuration(&source.path());
 
     // Get the highest priority, and the file its defined in.
     let attrpath = format!("options.{}.highestPrio", option_name);
@@ -97,93 +91,44 @@ pub fn get_highest_prio(
     let stdout = output.stdout();
     let highest_prio = i64::from_str(stdout.trim())?;
 
-    let needle = format!("lib.mkOverride ({})", highest_prio);
-
-    let path = source.path();
-    let lines = source.lines()?;
-    let line = lines
-        .iter()
-        // We're more likely to find it at the end, so let's start there.
-        .rev()
-        .find(|&line| line.text.contains(&needle))
-        .unwrap_or_else(|| {
-            panic!(
-                "couldn't find override number {highest_prio} in {}",
-                path.display(),
-            )
-        });
-
-    Ok((highest_prio, line.clone()))
+    Ok(highest_prio)
 }
 
 pub fn get_next_prio_line(
     source: SourceFile,
     option_name: Arc<str>,
-    last_line_def: SourceLine,
     new_prio: i64,
     new_value: Arc<str>,
 ) -> Result<SourceLine, BoxDynError> {
-    if !last_line_def.text.ends_with(';') {
-        todo!();
-    }
-    let next_line = source.line(last_line_def.line.next())?;
-    if next_line.text.trim() != "}" {
-        todo!();
-    }
-
-    let (indentation, _rest) = last_line_def.text.split_at(
-        last_line_def
-            .text
-            .find(|ch: char| !ch.is_ascii_whitespace())
-            .unwrap_or_default(),
-    );
-    // FIXME: fix indentation
-    let new_text = format!("{indentation}{option_name} = lib.mkOverride ({new_prio}) ({new_value});",);
+    let source_lines = source.lines()?;
+    let last_line = source_lines.last();
+    assert_eq!(last_line.map(SourceLine::text).as_deref(), Some("]"));
+    let last_line = last_line.unwrap();
 
     let new_line = SourceLine {
-        line: next_line.line.next(),
+        line: last_line.line,
         path: source.path(),
-        text: Arc::from(new_text),
+        text: Arc::from(format!(
+            "    {option_name} = lib.mkOverride ({new_prio}) ({new_value});",
+        )),
     };
 
     Ok(new_line)
 }
 
-pub fn write_next_prio(
-    mut source: SourceFile,
-    last_line_def: SourceLine,
-    new_text: Arc<str>,
-) -> Result<(), BoxDynError> {
-    //let lines = source.lines()?;
-
-    let open_brace_line = source.line(last_line_def.line.prev())?.text();
-    let close_brace_line = source.line(last_line_def.line.next())?.text();
-
+pub fn write_next_prio(mut source: SourceFile, new_line: SourceLine) -> Result<(), BoxDynError> {
     let new_mod_start = SourceLine {
-        line: last_line_def.line.next(),
+        line: new_line.line.prev(),
         path: source.path(),
-        text: open_brace_line,
-    };
-    let new_line = SourceLine {
-        line: new_mod_start.line.next(),
-        path: source.path(),
-        text: Arc::from(new_text),
+        text: Arc::from("  {"),
     };
     let new_mod_end = SourceLine {
         line: new_line.line.next(),
         path: source.path(),
-        text: close_brace_line,
+        text: Arc::from("  }"),
     };
 
-    dbg!(&new_mod_start.text());
-
-    source.insert_lines(&[
-        new_mod_start,
-        new_line,
-        new_mod_end,
-    ])?;
-
-    //source.insert_line(new_line.line, new_line.text())?;
+    source.insert_lines(&[new_mod_start, new_line, new_mod_end])?;
 
     Ok(())
 }