Extract constants from Nix to a new crate

Cargo.lock

@@ -119,6 +119,7 @@ dependencies = [
  "indexmap",
  "itertools",
  "la-arena",
+ "nix-interop",
  "ordered-float",
  "salsa",
  "smol_str",
@@ -268,6 +269,7 @@ dependencies = [
  "log",
  "lsp-server",
  "lsp-types",
+ "nix-interop",
  "serde",
  "serde_json",
  "text-size",
@@ -275,6 +277,10 @@ dependencies = [
  "tracing-subscriber",
 ]
 
+[[package]]
+name = "nix-interop"
+version = "0.0.0"
+
 [[package]]
 name = "num-traits"
 version = "0.2.15"

Cargo.toml

@@ -1,5 +1,11 @@
 [workspace]
-members = ["crates/*"]
+members = [
+    "crates/builtin",
+    "crates/ide",
+    "crates/nil",
+    "crates/nix-interop",
+    "crates/syntax",
+]
 
 [profile.dev]
 debug = 1

crates/ide/Cargo.toml

@@ -12,6 +12,7 @@ either = "1.8.0"
 indexmap = "1.9.1"
 itertools = "0.10.5"
 la-arena = "0.2.1"
+nix-interop = { path = "../nix-interop" }
 ordered-float = "3.4.0"
 salsa = "0.17.0-pre.2"
 smol_str = "0.1.23"

crates/ide/src/def/mod.rs

@@ -9,6 +9,7 @@ mod tests;
 use crate::base::SourceDatabase;
 use crate::{Diagnostic, FileId, SourceRootId, VfsPath};
 use la_arena::{Arena, ArenaMap, Idx};
+use nix_interop::DEFAULT_IMPORT_FILE;
 use ordered_float::OrderedFloat;
 use smol_str::SmolStr;
 use std::collections::{HashMap, HashSet};
@@ -154,7 +155,7 @@ impl Module {
                 };
                 let mut vpath = path.resolve(db)?;
                 source_root.file_for_path(&vpath).or_else(|| {
-                    vpath.push_segment("default.nix");
+                    vpath.push_segment(DEFAULT_IMPORT_FILE);
                     source_root.file_for_path(&vpath)
                 })
             })

crates/ide/src/tests.rs

@@ -4,6 +4,7 @@ use crate::ty::TyDatabaseStorage;
 use crate::{Change, DefDatabase, FileId, FilePos, FileRange, FileSet, SourceRoot, VfsPath};
 use anyhow::{ensure, Context, Result};
 use indexmap::IndexMap;
+use nix_interop::DEFAULT_IMPORT_FILE;
 use std::{mem, ops};
 use syntax::ast::AstNode;
 use syntax::{NixLanguage, SyntaxNode, TextSize};
@@ -37,7 +38,7 @@ impl TestDB {
             change.change_file(file, text.to_owned().into());
         }
         let entry = file_set
-            .file_for_path(&VfsPath::new("/default.nix").unwrap())
+            .file_for_path(&VfsPath::new(format!("/{DEFAULT_IMPORT_FILE}")).unwrap())
             .context("Missing entry file")?;
         change.set_roots(vec![SourceRoot::new_local(file_set, Some(entry))]);
         change.apply(&mut db);
@@ -109,7 +110,7 @@ impl Fixture {
             } else {
                 if cur_path.is_none() {
                     missing_header = true;
-                    cur_path = Some(VfsPath::new("/default.nix").unwrap());
+                    cur_path = Some(VfsPath::new(format!("/{DEFAULT_IMPORT_FILE}")).unwrap());
                 }
 
                 let mut iter = line.chars().peekable();

crates/nil/Cargo.toml

@@ -13,6 +13,7 @@ indexmap = "1.9.1"
 log = "0.4.17"
 lsp-server = "0.7.0"
 lsp-types = "0.93.0"
+nix-interop = { path = "../nix-interop" }
 serde = "1.0.140"
 serde_json = "1.0.82"
 text-size = "1.1.0"

crates/nil/src/handler.rs

@@ -10,12 +10,12 @@ use lsp_types::{
     SemanticTokensParams, SemanticTokensRangeParams, SemanticTokensRangeResult,
     SemanticTokensResult, TextDocumentPositionParams, TextEdit, Url, WorkspaceEdit,
 };
+use nix_interop::DEFAULT_IMPORT_FILE;
 use std::path::Path;
 use std::process;
 use std::sync::Arc;
 use text_size::TextRange;
 
-const DEFAULT_CHILD: &str = "default.nix";
 const MAX_DIAGNOSTICS_CNT: usize = 128;
 
 pub(crate) fn diagnostics(snap: StateSnapshot, uri: &Url) -> Result<Vec<Diagnostic>> {
@@ -37,7 +37,7 @@ pub(crate) fn goto_definition(
         None => return Ok(None),
         Some(GotoDefinitionResult::Path(vpath)) => {
             let path = Path::new(vpath.as_str());
-            let default_child = path.join(DEFAULT_CHILD);
+            let default_child = path.join(DEFAULT_IMPORT_FILE);
             let target_path = if path.is_file() {
                 path
             } else if default_child.is_file() {
@@ -280,7 +280,7 @@ pub(crate) fn document_links(
                 // FIXME: Duplicated with `goto_definition`.
                 LinkTarget::VfsPath(vpath) => {
                     let path = Path::new(vpath.as_str());
-                    let default_child = path.join(DEFAULT_CHILD);
+                    let default_child = path.join(DEFAULT_IMPORT_FILE);
                     let target_path = if path.is_file() {
                         path
                     } else if default_child.is_file() {

crates/nil/src/vfs.rs

@@ -117,14 +117,10 @@ impl Vfs {
     pub fn take_change(&mut self) -> Change {
         let mut change = mem::take(&mut self.change);
         if mem::take(&mut self.root_changed) {
-            // TODO: Configurable.
-            let entry = ["/flake.nix", "/default.nix"].iter().find_map(|&path| {
-                let path = VfsPath::new(path).unwrap();
-                self.local_file_set.file_for_path(&path)
-            });
             change.set_roots(vec![SourceRoot::new_local(
                 self.local_file_set.clone(),
-                entry,
+                // TODO: Entry.
+                None,
             )]);
         }
         change

crates/nix-interop/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "nix-interop"
+version = "0.0.0"
+edition = "2021"
+license = "MIT OR Apache-2.0"
+rust-version = "1.66"
+
+[dependencies]

crates/nix-interop/src/lib.rs

@@ -0,0 +1,4 @@
+//! Nix defined file structures and interoperation with Nix.
+pub const DEFAULT_IMPORT_FILE: &str = "default.nix";
+pub const FLAKE_FILE: &str = "flake.nix";
+pub const FLAKE_LOCK_FILE: &str = "flake.lock";