Add convenience methods to Manifest to iterate over requirements (#2701)

## Summary

These are repeated a bunch. It's nice to DRY them up and ensure the
ordering is consistent.

crates/uv-resolver/src/manifest.rs

@@ -1,5 +1,5 @@
 use distribution_types::LocalEditable;
-use pep508_rs::Requirement;
+use pep508_rs::{MarkerEnvironment, Requirement};
 use pypi_types::Metadata23;
 use uv_normalize::PackageName;
 use uv_types::RequestedRequirements;
@@ -74,4 +74,78 @@ impl Manifest {
             lookaheads: Vec::new(),
         }
     }
+
+    /// Return an iterator over all requirements, constraints, and overrides, in priority order,
+    /// such that requirements come first, followed by constraints, followed by overrides.
+    ///
+    /// At time of writing, this is used for:
+    /// - Determining which requirements should allow yanked versions.
+    /// - Determining which requirements should allow pre-release versions (e.g., `torch>=2.2.0a1`).
+    /// - Determining which requirements should allow direct URLs (e.g., `torch @ https://...`).
+    /// - Determining which requirements should allow local version specifiers (e.g., `torch==2.2.0+cpu`).
+    pub fn requirements<'a>(
+        &'a self,
+        markers: &'a MarkerEnvironment,
+    ) -> impl Iterator<Item = &Requirement> {
+        self.lookaheads
+            .iter()
+            .flat_map(|lookahead| {
+                lookahead
+                    .requirements()
+                    .iter()
+                    .filter(|requirement| requirement.evaluate_markers(markers, lookahead.extras()))
+            })
+            .chain(self.editables.iter().flat_map(|(editable, metadata)| {
+                metadata
+                    .requires_dist
+                    .iter()
+                    .filter(|requirement| requirement.evaluate_markers(markers, &editable.extras))
+            }))
+            .chain(
+                self.requirements
+                    .iter()
+                    .filter(|requirement| requirement.evaluate_markers(markers, &[])),
+            )
+            .chain(
+                self.constraints
+                    .iter()
+                    .filter(|requirement| requirement.evaluate_markers(markers, &[])),
+            )
+            .chain(
+                self.overrides
+                    .iter()
+                    .filter(|requirement| requirement.evaluate_markers(markers, &[])),
+            )
+    }
+
+    /// Return an iterator over the names of all direct dependency requirements.
+    ///
+    /// At time of writing, this is used for:
+    /// - Determining which packages should use the "lowest-compatible version" of a package, when
+    ///   the `lowest-direct` strategy is in use.
+    pub fn direct_dependencies<'a>(
+        &'a self,
+        markers: &'a MarkerEnvironment,
+    ) -> impl Iterator<Item = &PackageName> {
+        self.lookaheads
+            .iter()
+            .flat_map(|lookahead| {
+                lookahead
+                    .requirements()
+                    .iter()
+                    .filter(|requirement| requirement.evaluate_markers(markers, lookahead.extras()))
+            })
+            .chain(self.editables.iter().flat_map(|(editable, metadata)| {
+                metadata
+                    .requires_dist
+                    .iter()
+                    .filter(|requirement| requirement.evaluate_markers(markers, &editable.extras))
+            }))
+            .chain(
+                self.requirements
+                    .iter()
+                    .filter(|requirement| requirement.evaluate_markers(markers, &[])),
+            )
+            .map(|requirement| &requirement.name)
+    }
 }

crates/uv-resolver/src/prerelease_mode.rs

@@ -61,21 +61,7 @@ impl PreReleaseStrategy {
             PreReleaseMode::IfNecessary => Self::IfNecessary,
             PreReleaseMode::Explicit => Self::Explicit(
                 manifest
-                    .requirements
-                    .iter()
-                    .chain(manifest.constraints.iter())
-                    .chain(manifest.overrides.iter())
-                    .filter(|requirement| requirement.evaluate_markers(markers, &[]))
-                    .chain(manifest.lookaheads.iter().flat_map(|lookahead| {
-                        lookahead.requirements().iter().filter(|requirement| {
-                            requirement.evaluate_markers(markers, lookahead.extras())
-                        })
-                    }))
-                    .chain(manifest.editables.iter().flat_map(|(editable, metadata)| {
-                        metadata.requires_dist.iter().filter(|requirement| {
-                            requirement.evaluate_markers(markers, &editable.extras)
-                        })
-                    }))
+                    .requirements(markers)
                     .filter(|requirement| {
                         let Some(version_or_url) = &requirement.version_or_url else {
                             return false;
@@ -95,21 +81,7 @@ impl PreReleaseStrategy {
             ),
             PreReleaseMode::IfNecessaryOrExplicit => Self::IfNecessaryOrExplicit(
                 manifest
-                    .requirements
-                    .iter()
-                    .chain(manifest.constraints.iter())
-                    .chain(manifest.overrides.iter())
-                    .filter(|requirement| requirement.evaluate_markers(markers, &[]))
-                    .chain(manifest.lookaheads.iter().flat_map(|lookahead| {
-                        lookahead.requirements().iter().filter(|requirement| {
-                            requirement.evaluate_markers(markers, lookahead.extras())
-                        })
-                    }))
-                    .chain(manifest.editables.iter().flat_map(|(editable, metadata)| {
-                        metadata.requires_dist.iter().filter(|requirement| {
-                            requirement.evaluate_markers(markers, &editable.extras)
-                        })
-                    }))
+                    .requirements(markers)
                     .filter(|requirement| {
                         let Some(version_or_url) = &requirement.version_or_url else {
                             return false;

crates/uv-resolver/src/resolution_mode.rs

@@ -40,25 +40,9 @@ impl ResolutionStrategy {
         match mode {
             ResolutionMode::Highest => Self::Highest,
             ResolutionMode::Lowest => Self::Lowest,
-            ResolutionMode::LowestDirect => Self::LowestDirect(
-                // Consider `requirements` and dependencies of any local requirements to be "direct" dependencies.
-                manifest
-                    .requirements
-                    .iter()
-                    .filter(|requirement| requirement.evaluate_markers(markers, &[]))
-                    .chain(manifest.lookaheads.iter().flat_map(|lookahead| {
-                        lookahead.requirements().iter().filter(|requirement| {
-                            requirement.evaluate_markers(markers, lookahead.extras())
-                        })
-                    }))
-                    .chain(manifest.editables.iter().flat_map(|(editable, metadata)| {
-                        metadata.requires_dist.iter().filter(|requirement| {
-                            requirement.evaluate_markers(markers, &editable.extras)
-                        })
-                    }))
-                    .map(|requirement| requirement.name.clone())
-                    .collect(),
-            ),
+            ResolutionMode::LowestDirect => {
+                Self::LowestDirect(manifest.direct_dependencies(markers).cloned().collect())
+            }
         }
     }
 }

crates/uv-resolver/src/resolver/locals.rs

@@ -23,25 +23,8 @@ impl Locals {
         let mut required: FxHashMap<PackageName, Version> = FxHashMap::default();
 
         // Add all direct requirements and constraints. There's no need to look for conflicts,
-        // since conflicting versions will be tracked upstream.
-        for requirement in
-            manifest
-                .requirements
-                .iter()
-                .chain(manifest.constraints.iter())
-                .chain(manifest.overrides.iter())
-                .filter(|requirement| requirement.evaluate_markers(markers, &[]))
-                .chain(manifest.lookaheads.iter().flat_map(|lookahead| {
-                    lookahead.requirements().iter().filter(|requirement| {
-                        requirement.evaluate_markers(markers, lookahead.extras())
-                    })
-                }))
-                .chain(manifest.editables.iter().flat_map(|(editable, metadata)| {
-                    metadata.requires_dist.iter().filter(|requirement| {
-                        requirement.evaluate_markers(markers, &editable.extras)
-                    })
-                }))
-        {
+        // since conflicts will be enforced by the solver.
+        for requirement in manifest.requirements(markers) {
             if let Some(version_or_url) = requirement.version_or_url.as_ref() {
                 for local in iter_locals(version_or_url) {
                     required.insert(requirement.name.clone(), local);

crates/uv-resolver/src/version_map.rs

@@ -136,10 +136,10 @@ impl VersionMap {
     /// stored in this map. For example, the versions `1.2.0` and `1.2` are
     /// semantically equivalent, but when converted to strings, they are
     /// distinct.
-    pub(crate) fn get_with_version<'a>(
-        &'a self,
+    pub(crate) fn get_with_version(
+        &self,
         version: &Version,
-    ) -> Option<(&'a Version, &'a PrioritizedDist)> {
+    ) -> Option<(&Version, &PrioritizedDist)> {
         match self.inner {
             VersionMapInner::Eager(ref map) => map.get_key_value(version),
             VersionMapInner::Lazy(ref lazy) => lazy.get_with_version(version),

crates/uv-resolver/src/yanks.rs

@@ -4,8 +4,7 @@ use pep440_rs::Version;
 use pep508_rs::{MarkerEnvironment, VersionOrUrl};
 use uv_normalize::PackageName;
 
-use crate::preferences::Preference;
-use crate::Manifest;
+use crate::{Manifest, Preference};
 
 /// A set of package versions that are permitted, even if they're marked as yanked by the
 /// relevant index.
@@ -15,24 +14,9 @@ pub struct AllowedYanks(FxHashMap<PackageName, FxHashSet<Version>>);
 impl AllowedYanks {
     pub fn from_manifest(manifest: &Manifest, markers: &MarkerEnvironment) -> Self {
         let mut allowed_yanks = FxHashMap::<PackageName, FxHashSet<Version>>::default();
-        for requirement in
-            manifest
-                .requirements
-                .iter()
-                .chain(manifest.constraints.iter())
-                .chain(manifest.overrides.iter())
+        for requirement in manifest
+            .requirements(markers)
             .chain(manifest.preferences.iter().map(Preference::requirement))
-                .filter(|requirement| requirement.evaluate_markers(markers, &[]))
-                .chain(manifest.lookaheads.iter().flat_map(|lookahead| {
-                    lookahead.requirements().iter().filter(|requirement| {
-                        requirement.evaluate_markers(markers, lookahead.extras())
-                    })
-                }))
-                .chain(manifest.editables.iter().flat_map(|(editable, metadata)| {
-                    metadata.requires_dist.iter().filter(|requirement| {
-                        requirement.evaluate_markers(markers, &editable.extras)
-                    })
-                }))
         {
             let Some(VersionOrUrl::VersionSpecifier(specifiers)) = &requirement.version_or_url
             else {

crates/uv/tests/pip_compile.rs

@@ -1815,6 +1815,85 @@ fn allowed_transitive_url_path_dependency() -> Result<()> {
     Ok(())
 }
 
+/// A dependency with conflicting URLs in `requirements.in` and `constraints.txt` should arguably
+/// be ignored if the dependency has an override. However, we currently error in this case.
+#[test]
+fn requirement_constraint_override_url() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let requirements_in = context.temp_dir.child("requirements.in");
+    requirements_in.write_str("anyio @ https://files.pythonhosted.org/packages/db/4d/3970183622f0330d3c23d9b8a5f52e365e50381fd484d08e3285104333d3/anyio-4.3.0.tar.gz")?;
+
+    let constraints_txt = context.temp_dir.child("constraints.txt");
+    constraints_txt.write_str("anyio @ https://files.pythonhosted.org/packages/14/fd/2f20c40b45e4fb4324834aea24bd4afdf1143390242c0b33774da0e2e34f/anyio-4.3.0-py3-none-any.whl")?;
+
+    let overrides_txt = context.temp_dir.child("overrides.txt");
+    overrides_txt.write_str("anyio==3.7.0")?;
+
+    uv_snapshot!(context.compile()
+        .arg("requirements.in")
+        .arg("--constraint")
+        .arg("constraints.txt")
+        .arg("--override")
+        .arg("overrides.txt"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    error: Requirements contain conflicting URLs for package `anyio`:
+    - https://files.pythonhosted.org/packages/db/4d/3970183622f0330d3c23d9b8a5f52e365e50381fd484d08e3285104333d3/anyio-4.3.0.tar.gz
+    - https://files.pythonhosted.org/packages/14/fd/2f20c40b45e4fb4324834aea24bd4afdf1143390242c0b33774da0e2e34f/anyio-4.3.0-py3-none-any.whl
+    "###
+    );
+
+    Ok(())
+}
+
+/// A dependency that uses a pre-release marker in `requirements.in` should be overridden by a
+/// non-pre-release version in `overrides.txt`. We currently allow Flask to use a pre-release below,
+/// but probably shouldn't.
+#[test]
+fn requirement_override_prerelease() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let requirements_in = context.temp_dir.child("requirements.in");
+    requirements_in.write_str("flask<2.0.0rc4")?;
+
+    let overrides_txt = context.temp_dir.child("overrides.txt");
+    overrides_txt.write_str("flask<2.0.1,!=2.0.0")?;
+
+    uv_snapshot!(context.compile()
+        .arg("requirements.in")
+        .arg("--override")
+        .arg("overrides.txt"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] --exclude-newer 2024-03-25T00:00:00Z requirements.in --override overrides.txt
+    click==8.1.7
+        # via flask
+    flask==2.0.0rc2
+    itsdangerous==2.1.2
+        # via flask
+    jinja2==3.1.3
+        # via flask
+    markupsafe==2.1.5
+        # via
+        #   jinja2
+        #   werkzeug
+    werkzeug==3.0.1
+        # via flask
+
+    ----- stderr -----
+    Resolved 6 packages in [TIME]
+    "###
+    );
+
+    Ok(())
+}
+
 /// Resolve packages from all optional dependency groups in a `pyproject.toml` file.
 #[test]
 fn compile_pyproject_toml_all_extras() -> Result<()> {