Add WIP package crate

Cargo.toml

@@ -6,6 +6,7 @@ members = [
     "vector",
     "lsp/nls",
     "lsp/lsp-harness",
+    "package",
     "utils",
     "wasm-repl",
     "pyckel",
@@ -25,6 +26,7 @@ readme = "README.md"
 [workspace.dependencies]
 nickel-lang-core = { version = "0.10.0", path = "./core", default-features = false }
 nickel-lang-git = { version = "0.1.0", path = "./git" }
+nickel-lang-package = { version = "0.1.0", path = "./package" }
 nickel-lang-vector = { version = "0.1.0", path = "./vector" }
 nickel-lang-utils = { version = "0.1.0", path = "./utils" }
 lsp-harness = { version = "0.1.0", path = "./lsp/lsp-harness" }
@@ -58,6 +60,7 @@ directories = "4.0.1"
 env_logger = "0.10"
 git-version = "0.3.5"
 gix = "0.67.0"
+gix-hash = "0.15.0"
 indexmap = "1.9.3"
 indoc = "2"
 insta = "1.29.0"

package/Cargo.toml

@@ -0,0 +1,35 @@
+[package]
+name = "nickel-lang-package"
+description = "The Nickel Package Manager (npm)"
+version = "0.1.0"
+
+authors.workspace = true
+edition.workspace = true
+homepage.workspace = true
+keywords.workspace = true
+license.workspace = true
+repository.workspace = true
+readme.workspace = true
+
+[features]
+
+[dependencies]
+anyhow.workspace = true
+directories.workspace = true
+gix.workspace = true
+gix-hash = { workspace = true, features = ["serde"] }
+nickel-lang-core = { workspace = true, default-features = false }
+nickel-lang-git.workspace = true
+pubgrub = { version = "0.2.1", features = ["serde"] }
+regex.workspace = true
+semver = { version = "1.0.23", features = ["serde"] }
+serde.workspace = true
+serde_json.workspace = true
+serde_with.workspace = true
+tempfile = { workspace = true }
+thiserror.workspace = true
+
+[dev-dependencies]
+insta = { workspace = true, features = ["filters"] }
+nickel-lang-utils.workspace = true
+test-generator.workspace = true

package/src/config.rs

@@ -0,0 +1,66 @@
+use std::path::PathBuf;
+
+use directories::ProjectDirs;
+use std::collections::HashMap;
+
+const DEFAULT_INDEX_URL: &str = "https://github.com/nickel-lang/nickel-mine.git";
+
+/// Global configuration for the package manager.
+#[derive(Clone, Debug)]
+pub struct Config {
+    pub index_url: gix::Url,
+
+    pub cache_dir: PathBuf,
+
+    /// Defaults to `<cache_dir>/index`
+    pub index_dir: PathBuf,
+    /// Defaults to `<cache_dir>/index-packages`
+    pub index_package_dir: PathBuf,
+    /// Defaults to `<cache_dir>/git-packages`
+    pub git_package_dir: PathBuf,
+
+    /// Git source replacements: any git packages that we're supposed to
+    /// fetch from the original source will be transparently fetched from the
+    /// replacement source instead. The lock-file will not see this replacement;
+    /// it's intended for vendoring or mirroring, not changing the contents of
+    /// the package.
+    pub git_replacements: HashMap<gix::Url, gix::Url>,
+    // TODO: index replacments (and private indices)
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        // unwrap: TODO
+        let cache_dir = ProjectDirs::from("org", "nickel-lang", "nickel")
+            .unwrap()
+            .cache_dir()
+            .to_owned();
+        Self {
+            // unwrap: it's a constant, and we know it's a valid url.
+            index_url: DEFAULT_INDEX_URL.try_into().unwrap(),
+            index_dir: PathBuf::default(),
+            index_package_dir: PathBuf::default(),
+            git_package_dir: PathBuf::default(),
+            cache_dir: PathBuf::default(),
+            git_replacements: HashMap::default(),
+        }
+        .with_cache_dir(cache_dir)
+    }
+}
+
+impl Config {
+    /// Configures the root cache directory, and reconfigures the various derived paths
+    /// based on the new root cache directory.
+    pub fn with_cache_dir(self, cache_dir: PathBuf) -> Self {
+        Self {
+            index_dir: cache_dir.join("index"),
+            index_package_dir: cache_dir.join("index-packages"),
+            git_package_dir: cache_dir.join("git-packages"),
+            ..self
+        }
+    }
+
+    pub fn with_index_dir(self, index_dir: PathBuf) -> Self {
+        Self { index_dir, ..self }
+    }
+}