Add release module

The new `Release` struct encapsulates `Distribution` and adds a
`release` field that contains JWS-signed release metadata. It currently
only supports v2 metadata, but offers the same traits, constructors, and
accessors as `Distribution`, plus the `release()` accessor and
associated objects.

Add tests for all of these bits, using both the v2 corpus with a release
patch applied and custom JSON objects to test each individual struct and
its accessors.

Writing the tests for the `TryFrom<PathBuf>` when what was on hand was a
`Path` led to a bit of research and the conclusion that one does not
convert a file path into a struct, but loads it into a struct. So create
the `load` function, instead, and have it accept a `AsRef<Path>`
argument, which covers `Path`s, `PathBuf`s, and strings. Back-patch this
change to `Distribution`, as well, and take advantage of `.try_into()`
where possible.

Cargo.toml

@@ -16,13 +16,15 @@ exclude = [ ".github", ".vscode", ".gitignore", ".ci", ".pre-*.yaml"]
 
 [dependencies]
 boon = "0.6"
+chrono = { version = "0.4.38", features = ["serde"] }
 email_address = "0.2.9"
 json-patch = "2.0.0"
 lexopt = "0.3.0"
 relative-path = { version = "1.9", features = ["serde"] }
 semver = { version = "1.0", features = ["std", "serde"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1.0"
+serde_with = { version = "3.9.0", features = ["hex"] }
 spdx = "0.10.6"
 wax = "0.6.0"
 
@@ -32,3 +34,5 @@ serde_json = "1.0"
 
 [dev-dependencies]
 assert-json-diff = "2.0.2"
+hex = "0.4.3"
+tempfile = "3.12.0"

src/lib.rs

@@ -12,6 +12,7 @@ files. It supports both the [v1] and [v2] specs.
 */
 
 pub mod meta;
+pub mod release;
 mod util; // private utilities
 pub mod valid;
 

src/meta/mod.rs

@@ -8,7 +8,7 @@ This module provides interfaces to load, validate, and manipulate PGXN
   [v2]: https://github.com/pgxn/rfcs/pull/3
 
 */
-use std::{borrow::Borrow, collections::HashMap, error::Error, fs::File, path::PathBuf};
+use std::{borrow::Borrow, collections::HashMap, error::Error, fs::File, path::Path};
 
 use crate::util;
 use relative_path::{RelativePath, RelativePathBuf};
@@ -836,6 +836,14 @@ impl Distribution {
         }
     }
 
+    /// Loads the release `META.json` data from `file` then converts into a
+    /// [`Distribution`]. Returns an error on file error or if the content of
+    /// `file` is not valid PGXN `META.json` data.
+    pub fn load<P: AsRef<Path>>(file: P) -> Result<Self, Box<dyn Error>> {
+        let meta: Value = serde_json::from_reader(File::open(file)?)?;
+        meta.try_into()
+    }
+
     /// Borrows the Distribution name.
     pub fn name(&self) -> &str {
         self.name.as_str()
@@ -1073,24 +1081,13 @@ impl TryFrom<Distribution> for Value {
     }
 }
 
-impl TryFrom<&PathBuf> for Distribution {
-    type Error = Box<dyn Error>;
-    /// Reads the `META.json` data from `file` then converts into a
-    /// [`Distribution`]. Returns an error on file error or if the content of
-    /// `file` is not valid PGXN `META.json` data.
-    fn try_from(file: &PathBuf) -> Result<Self, Self::Error> {
-        let meta: Value = serde_json::from_reader(File::open(file)?)?;
-        Distribution::try_from(meta)
-    }
-}
-
 impl TryFrom<&String> for Distribution {
     type Error = Box<dyn Error>;
     /// Converts `str` into JSON and then into  a [`Distribution`]. Returns an
     /// error if the content of `str` is not valid PGXN `META.json` data.
     fn try_from(str: &String) -> Result<Self, Self::Error> {
         let meta: Value = serde_json::from_str(str)?;
-        Distribution::try_from(meta)
+        meta.try_into()
     }
 }
 

src/meta/tests.rs

@@ -19,8 +19,8 @@ fn test_corpus() -> Result<(), Box<dyn Error>> {
             let path = path?.into_path();
             let contents: Value = serde_json::from_reader(File::open(&path)?)?;
 
-            // Test try_from path.
-            if let Err(e) = Distribution::try_from(&path) {
+            // Test load path.
+            if let Err(e) = Distribution::load(&path) {
                 panic!("{v_dir}/{:?} failed: {e}", path.file_name().unwrap());
             }
 
@@ -1347,7 +1347,7 @@ fn test_distribution() -> Result<(), Box<dyn Error>> {
         let name = path.as_path().to_str().unwrap();
         let contents: Value = serde_json::from_reader(File::open(&path)?)?;
 
-        match Distribution::try_from(&path) {
+        match Distribution::load(&path) {
             Err(e) => panic!("{name} failed: {e}"),
             Ok(dist) => {
                 // Required fields.

src/meta/v1/tests.rs

@@ -1,4 +1,5 @@
 use super::*;
+use std::path::PathBuf;
 
 #[test]
 fn test_v1_v2_common() {