refactor: migrate deps-cargo and deps-pypi from toml_edit to toml-span (#65) (#69)

Replace toml_edit with toml-span in both Cargo.toml and pyproject.toml
parsers. toml-span provides reliable span tracking for all values
including inline tables, eliminating text-search fallbacks for position
tracking.

- Rewrite deps-cargo parser to use toml_span::parse() with Value.span
- Rewrite deps-pypi parser, removing find_dependency_string_position
  and find_table_key_position workarounds
- Migrate lockfile parsers in both crates
- Remove toml_edit from workspace dependencies entirely

Author: bug-ops

CHANGELOG.md

@@ -21,6 +21,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **Google Maven repository support** — Android packages (`androidx.*`, `com.google.firebase.*`, `com.google.android.*`, `com.android.*`) now resolve from Google Maven instead of Maven Central
 
 ### Changed
+- **Migrate deps-cargo and deps-pypi from toml_edit to toml-span** — Reliable span tracking for all values including inline tables; eliminates text-search fallbacks for position tracking
+- Remove `toml_edit` from workspace dependencies (all TOML parsers now use `toml-span`)
 - Extract `LineOffsetTable` and `position_in_range` to deps-core for reuse across ecosystems
 - Extract `complete_package_names_generic` to deps-core completion module
 

Cargo.lock

@@ -42,7 +42,6 @@ tempfile = "3"
 thiserror = "2"
 tokio = "1.49"
 tokio-test = "0.4"
-toml_edit = "0.25"
 toml-span = "0.7"
 tower-lsp-server = "0.23"
 tracing = "0.1"

Cargo.toml

@@ -20,7 +20,7 @@ serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
 thiserror = { workspace = true }
 tokio = { workspace = true, features = ["fs"] }
-toml_edit = { workspace = true }
+toml-span = { workspace = true }
 tower-lsp-server = { workspace = true }
 tracing = { workspace = true }
 urlencoding = { workspace = true }

crates/deps-cargo/Cargo.toml

@@ -11,7 +11,7 @@ This crate provides parsing and registry integration for Rust's Cargo ecosystem.
 
 ## Features
 
-- **TOML Parsing** — Parse `Cargo.toml` with position tracking using `toml_edit`
+- **TOML Parsing** — Parse `Cargo.toml` with position tracking using `toml-span`
 - **Lock File Parsing** — Extract resolved versions from `Cargo.lock`
 - **crates.io Registry** — Sparse index client for package metadata
 - **Version Resolution** — Semver-aware version matching

crates/deps-cargo/README.md

@@ -12,11 +12,8 @@ use thiserror::Error;
 #[derive(Error, Debug)]
 pub enum CargoError {
     /// Failed to parse Cargo.toml
-    #[error("Failed to parse Cargo.toml: {source}")]
-    TomlParseError {
-        #[source]
-        source: toml_edit::TomlError,
-    },
+    #[error("Failed to parse Cargo.toml: {message}")]
+    TomlParseError { message: String },
 
     /// Invalid semver version specifier
     #[error("Invalid semver version specifier '{specifier}': {message}")]
@@ -157,9 +154,9 @@ impl From<deps_core::DepsError> for CargoError {
 impl From<CargoError> for deps_core::DepsError {
     fn from(err: CargoError) -> Self {
         match err {
-            CargoError::TomlParseError { source } => Self::ParseError {
+            CargoError::TomlParseError { message } => Self::ParseError {
                 file_type: "Cargo.toml".into(),
-                source: Box::new(source),
+                source: Box::new(std::io::Error::other(message)),
             },
             CargoError::InvalidVersionSpecifier { message, .. } => Self::InvalidVersionReq(message),
             CargoError::PackageNotFound { package } => {

crates/deps-cargo/src/error.rs

@@ -29,7 +29,6 @@ use deps_core::lockfile::{
     locate_lockfile_for_manifest,
 };
 use std::path::{Path, PathBuf};
-use toml_edit::DocumentMut;
 use tower_lsp_server::ls_types::Uri;
 
 /// Cargo.lock file parser.
@@ -84,42 +83,46 @@ impl LockFileProvider for CargoLockParser {
                 source: Box::new(e),
             })?;
 
-        let doc: DocumentMut = content.parse().map_err(|e| DepsError::ParseError {
+        let doc = toml_span::parse(&content).map_err(|e| DepsError::ParseError {
             file_type: "Cargo.lock".into(),
-            source: Box::new(e),
+            source: Box::new(std::io::Error::other(e.to_string())),
         })?;
 
         let mut packages = ResolvedPackages::new();
 
-        let Some(package_array) = doc
-            .get("package")
-            .and_then(|v: &toml_edit::Item| v.as_array_of_tables())
-        else {
+        let Some(root_table) = doc.as_table() else {
+            tracing::warn!("Cargo.lock root is not a table");
+            return Ok(packages);
+        };
+
+        let Some(package_array_val) = root_table.get("package") else {
             tracing::warn!("Cargo.lock missing [[package]] array of tables");
             return Ok(packages);
         };
 
-        for table in package_array {
+        let Some(package_array) = package_array_val.as_array() else {
+            tracing::warn!("Cargo.lock [[package]] is not an array");
+            return Ok(packages);
+        };
+
+        for entry in package_array {
+            let Some(table) = entry.as_table() else {
+                continue;
+            };
+
             // Extract required fields
-            let Some(name) = table.get("name").and_then(|v: &toml_edit::Item| v.as_str()) else {
+            let Some(name) = table.get("name").and_then(|v| v.as_str()) else {
                 tracing::warn!("Package missing name field");
                 continue;
             };
 
-            let Some(version) = table
-                .get("version")
-                .and_then(|v: &toml_edit::Item| v.as_str())
-            else {
+            let Some(version) = table.get("version").and_then(|v| v.as_str()) else {
                 tracing::warn!("Package '{}' missing version field", name);
                 continue;
             };
 
             // Parse source (optional for path dependencies)
-            let source = parse_cargo_source(
-                table
-                    .get("source")
-                    .and_then(|v: &toml_edit::Item| v.as_str()),
-            );
+            let source = parse_cargo_source(table.get("source").and_then(|v| v.as_str()));
 
             // Parse dependencies array (optional)
             let dependencies = parse_cargo_dependencies_from_table(table);
@@ -182,7 +185,7 @@ fn parse_cargo_source(source_str: Option<&str>) -> ResolvedSource {
 /// ```toml
 /// dependencies = ["serde_derive", "syn"]
 /// ```
-fn parse_cargo_dependencies_from_table(table: &toml_edit::Table) -> Vec<String> {
+fn parse_cargo_dependencies_from_table(table: &toml_span::value::Table<'_>) -> Vec<String> {
     let Some(deps_value) = table.get("dependencies") else {
         return vec![];
     };
@@ -199,9 +202,9 @@ fn parse_cargo_dependencies_from_table(table: &toml_edit::Table) -> Vec<String>
                 return Some(s.to_string());
             }
 
-            // Inline table format (rare, extract "name" field)
-            if let Some(table) = item.as_inline_table()
-                && let Some(name) = table.get("name").and_then(|v| v.as_str())
+            // Table format (rare, extract "name" field)
+            if let Some(t) = item.as_table()
+                && let Some(name) = t.get("name").and_then(|v| v.as_str())
             {
                 return Some(name.to_string());
             }