Add full python core metadata support; fixes #159

konstin · konstin · commit 5b0e4808bb88 · 2019-07-05T12:35:02.000+02:00
diff --git a/Changelog.md b/Changelog.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  * Mixed rust/python layout
  * Added PEP 517 support
  * Added a `pyo-pack sdist` command as workaround for [pypa/pip#6041](https://github.com/pypa/pip/issues/6041)
+ * Support settings all applicable fields from the python core metadata specification in Cargo.toml
 
 ## [0.6.1]
 
diff --git a/Readme.md b/Readme.md
@@ -98,20 +98,28 @@ my-project
 
 ## Python metadata
 
+To specifiy python dependecies, add a list `requires-dist` in a `[package.metadata.pyo3-pack]` section in the Cargo.toml. This list is equivalent to `install_requires` in setuptools:
+
+```toml
+[package.metadata.pyo3-pack]
+requires-dist = ["flask~=1.1.0", "toml==0.10.0"]
+```
+
 Pip allows adding so called console scripts, which are shell commands that execute some function in you program. You can add console scripts in a section `[package.metadata.pyo3-pack.scripts]`. The keys are the script names while the values are the path to the function in the format `some.module.path:class.function`, where the `class` part is optional. The function is called with no arguments. Example:
 
 ```toml
 [package.metadata.pyo3-pack.scripts]
 get_42 = "my_project:DummyClass.get_42"
 ```
 
-You can also specify [trove classifiers](https://pypi.org/classifiers/) in your Cargo.toml under `package.metadata.pyo3-pack.classifier`, e.g.:
+You can also specify [trove classifiers](https://pypi.org/classifiers/) in your Cargo.toml under `package.metadata.pyo3-pack.classifier`:
 
 ```toml
 [package.metadata.pyo3-pack]
 classifier = ["Programming Language :: Python"]
 ```
 
+You can use other fields from the [python core metadata](https://packaging.python.org/specifications/core-metadata/) in the `[package.metadata.pyo3-pack]` section, specifically ` maintainer`, `maintainer-email` and `requires-python` (string fields), as well as `requires-external`, `project-url` and `provides-extra` (lists of strings).
 
 ## pyproject.toml
 
diff --git a/src/cargo_toml.rs b/src/cargo_toml.rs
@@ -61,7 +61,7 @@ impl CargoToml {
         match self.package.metadata {
             Some(CargoTomlMetadata {
                 pyo3_pack:
-                    Some(CargoTomlMetadataPyo3Pack {
+                    Some(RemainingCoreMetadata {
                         scripts: Some(ref scripts),
                         ..
                     }),
@@ -75,26 +75,49 @@ impl CargoToml {
         match self.package.metadata {
             Some(CargoTomlMetadata {
                 pyo3_pack:
-                    Some(CargoTomlMetadataPyo3Pack {
+                    Some(RemainingCoreMetadata {
                         classifier: Some(ref classifier),
                         ..
                     }),
             }) => classifier.clone(),
             _ => Vec::new(),
         }
     }
+
+    /// Returns the value of `[project.metadata.pyo3-pack]` or an empty stub
+    pub fn remaining_core_metadata(&self) -> RemainingCoreMetadata {
+        match &self.package.metadata {
+            Some(CargoTomlMetadata {
+                pyo3_pack: Some(extra_metadata),
+            }) => extra_metadata.clone(),
+            _ => Default::default(),
+        }
+    }
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, Eq, PartialEq)]
+#[serde(rename_all = "kebab-case")]
 struct CargoTomlMetadata {
-    #[serde(rename = "pyo3-pack")]
-    pyo3_pack: Option<CargoTomlMetadataPyo3Pack>,
+    pyo3_pack: Option<RemainingCoreMetadata>,
 }
 
-#[derive(Serialize, Deserialize, Debug, Clone, Eq, PartialEq)]
-struct CargoTomlMetadataPyo3Pack {
-    scripts: Option<HashMap<String, String>>,
-    classifier: Option<Vec<String>>,
+/// The `[project.metadata.pyo3-pack]` with the python specific metadata
+///
+/// Those fields are the part of the
+/// [python core metadata](https://packaging.python.org/specifications/core-metadata/)
+/// that doesn't have an equivalent in cargo's `[package]` table
+#[derive(Serialize, Deserialize, Debug, Clone, Eq, PartialEq, Default)]
+#[serde(rename_all = "kebab-case")]
+pub struct RemainingCoreMetadata {
+    pub scripts: Option<HashMap<String, String>>,
+    pub classifier: Option<Vec<String>>,
+    pub maintainer: Option<String>,
+    pub maintainer_email: Option<String>,
+    pub requires_dist: Option<Vec<String>>,
+    pub requires_python: Option<String>,
+    pub requires_external: Option<Vec<String>>,
+    pub project_url: Option<Vec<String>>,
+    pub provides_extra: Option<Vec<String>>,
 }
 
 #[cfg(test)]
@@ -124,6 +147,7 @@ mod test {
 
             [package.metadata.pyo3-pack]
             classifier = ["Programming Language :: Python"]
+            requires-dist = ["flask~=1.1.0", "toml==0.10.0"]
         "#
         );
 
@@ -134,7 +158,13 @@ mod test {
 
         let classifier = vec!["Programming Language :: Python".to_string()];
 
+        let requires_dist = Some(vec!["flask~=1.1.0".to_string(), "toml==0.10.0".to_string()]);
+
         assert_eq!(cargo_toml.scripts(), scripts);
         assert_eq!(cargo_toml.classifier(), classifier);
+        assert_eq!(
+            cargo_toml.remaining_core_metadata().requires_dist,
+            requires_dist
+        );
     }
 }
diff --git a/src/metadata.rs b/src/metadata.rs
@@ -85,12 +85,14 @@ impl Metadata21 {
 
         let classifier = cargo_toml.classifier();
 
+        let extra_metadata = cargo_toml.remaining_core_metadata();
+
         Ok(Metadata21 {
             metadata_version: "2.1".to_owned(),
+
+            // Mapped from cargo metadata
             name: cargo_toml.package.name.to_owned(),
             version: cargo_toml.package.version.clone(),
-            platform: Vec::new(),
-            supported_platform: Vec::new(),
             summary: cargo_toml.package.description.clone(),
             description,
             description_content_type,
@@ -104,17 +106,25 @@ impl Metadata21 {
             // Cargo.toml has no distinction between author and author email
             author: Some(authors.to_owned()),
             author_email: Some(authors.to_owned()),
-            maintainer: None,
-            maintainer_email: None,
             license: cargo_toml.package.license.clone(),
+
+            // Values provided through `[project.metadata.pyo3-pack]`
             classifier,
-            requires_dist: Vec::new(),
+            maintainer: extra_metadata.maintainer,
+            maintainer_email: extra_metadata.maintainer_email,
+            requires_dist: extra_metadata.requires_dist.unwrap_or_default(),
+            requires_python: extra_metadata.requires_python,
+            requires_external: extra_metadata.requires_external.unwrap_or_default(),
+            project_url: extra_metadata.project_url.unwrap_or_default(),
+            provides_extra: extra_metadata.provides_extra.unwrap_or_default(),
+
+            // Officially rarely used, and afaik not applicable with pyo3
             provides_dist: Vec::new(),
             obsoletes_dist: Vec::new(),
-            requires_python: None,
-            requires_external: Vec::new(),
-            project_url: Vec::new(),
-            provides_extra: Vec::new(),
+
+            // Open question: Should those also be supported? And if so, how?
+            platform: Vec::new(),
+            supported_platform: Vec::new(),
         })
     }
 
@@ -281,6 +291,7 @@ mod test {
 
             [package.metadata.pyo3-pack]
             classifier = ["Programming Language :: Python"]
+            requires-dist = ["flask~=1.1.0", "toml==0.10.0"]
         "#
         )
         .replace("readme.md", &readme_path);
@@ -296,6 +307,8 @@ mod test {
             Name: info-project
             Version: 0.1.0
             Classifier: Programming Language :: Python
+            Requires-Dist: flask~=1.1.0
+            Requires-Dist: toml==0.10.0
             Summary: A test project
             Keywords: ffi test
             Home-Page: https://example.org
