Make check-url available in configuration files (#9032)

## Summary

Fixes #9027

Minor enhancement on top of #8531 that makes the CLI parameter
`--check-url` also available as the setting `check-url` in configuration
files.

## Test Plan

Updates existing tests to take the new setting into account.

Within publish command testing I didn't see existing tests covering
settings from toml files (instead of from CLI params), so I didn't add
anything of that sort.

crates/uv-settings/src/settings.rs

@@ -6,7 +6,9 @@ use uv_configuration::{
     ConfigSettings, IndexStrategy, KeyringProviderType, PackageNameSpecifier, TargetTriple,
     TrustedHost, TrustedPublishing,
 };
-use uv_distribution_types::{Index, PipExtraIndex, PipFindLinks, PipIndex, StaticMetadata};
+use uv_distribution_types::{
+    Index, IndexUrl, PipExtraIndex, PipFindLinks, PipIndex, StaticMetadata,
+};
 use uv_install_wheel::linker::LinkMode;
 use uv_macros::{CombineOptions, OptionsMetadata};
 use uv_normalize::{ExtraName, PackageName};
@@ -1622,6 +1624,7 @@ pub struct OptionsWire {
     // publish: PublishOptions
     publish_url: Option<Url>,
     trusted_publishing: Option<TrustedPublishing>,
+    check_url: Option<IndexUrl>,
 
     pip: Option<PipOptions>,
     cache_keys: Option<Vec<CacheKey>>,
@@ -1698,6 +1701,7 @@ impl From<OptionsWire> for Options {
             conflicts,
             publish_url,
             trusted_publishing,
+            check_url,
             workspace,
             sources,
             default_groups,
@@ -1763,6 +1767,7 @@ impl From<OptionsWire> for Options {
             publish: PublishOptions {
                 publish_url,
                 trusted_publishing,
+                check_url,
             },
             workspace,
             sources,
@@ -1804,4 +1809,26 @@ pub struct PublishOptions {
         "#
     )]
     pub trusted_publishing: Option<TrustedPublishing>,
+
+    /// Check an index URL for existing files to skip duplicate uploads.
+    ///
+    /// This option allows retrying publishing that failed after only some, but not all files have
+    /// been uploaded, and handles error due to parallel uploads of the same file.
+    ///
+    /// Before uploading, the index is checked. If the exact same file already exists in the index,
+    /// the file will not be uploaded. If an error occurred during the upload, the index is checked
+    /// again, to handle cases where the identical file was uploaded twice in parallel.
+    ///
+    /// The exact behavior will vary based on the index. When uploading to PyPI, uploading the same
+    /// file succeeds even without `--check-url`, while most other indexes error.
+    ///
+    /// The index must provide one of the supported hashes (SHA-256, SHA-384, or SHA-512).
+    #[option(
+        default = "None",
+        value_type = "str",
+        example = r#"
+            check-url = "https://test.pypi.org/simple"
+        "#
+    )]
+    pub check_url: Option<IndexUrl>,
 }

crates/uv/src/settings.rs

@@ -2829,6 +2829,7 @@ impl PublishSettings {
         let PublishOptions {
             publish_url,
             trusted_publishing,
+            check_url,
         } = publish;
         let ResolverInstallerOptions {
             keyring_provider, ..
@@ -2856,7 +2857,7 @@ impl PublishSettings {
                 .keyring_provider
                 .combine(keyring_provider)
                 .unwrap_or_default(),
-            check_url: args.check_url,
+            check_url: args.check_url.combine(check_url),
         }
     }
 }

crates/uv/tests/it/show_settings.rs

@@ -3443,7 +3443,7 @@ fn resolve_config_file() -> anyhow::Result<()> {
       |
     1 | [project]
       |  ^^^^^^^
-    unknown field `project`, expected one of `native-tls`, `offline`, `no-cache`, `cache-dir`, `preview`, `python-preference`, `python-downloads`, `concurrent-downloads`, `concurrent-builds`, `concurrent-installs`, `index`, `index-url`, `extra-index-url`, `no-index`, `find-links`, `index-strategy`, `keyring-provider`, `allow-insecure-host`, `resolution`, `prerelease`, `dependency-metadata`, `config-settings`, `no-build-isolation`, `no-build-isolation-package`, `exclude-newer`, `link-mode`, `compile-bytecode`, `no-sources`, `upgrade`, `upgrade-package`, `reinstall`, `reinstall-package`, `no-build`, `no-build-package`, `no-binary`, `no-binary-package`, `python-install-mirror`, `pypy-install-mirror`, `publish-url`, `trusted-publishing`, `pip`, `cache-keys`, `override-dependencies`, `constraint-dependencies`, `environments`, `conflicts`, `workspace`, `sources`, `managed`, `package`, `default-groups`, `dev-dependencies`, `build-backend`
+    unknown field `project`, expected one of `native-tls`, `offline`, `no-cache`, `cache-dir`, `preview`, `python-preference`, `python-downloads`, `concurrent-downloads`, `concurrent-builds`, `concurrent-installs`, `index`, `index-url`, `extra-index-url`, `no-index`, `find-links`, `index-strategy`, `keyring-provider`, `allow-insecure-host`, `resolution`, `prerelease`, `dependency-metadata`, `config-settings`, `no-build-isolation`, `no-build-isolation-package`, `exclude-newer`, `link-mode`, `compile-bytecode`, `no-sources`, `upgrade`, `upgrade-package`, `reinstall`, `reinstall-package`, `no-build`, `no-build-package`, `no-binary`, `no-binary-package`, `python-install-mirror`, `pypy-install-mirror`, `publish-url`, `trusted-publishing`, `check-url`, `pip`, `cache-keys`, `override-dependencies`, `constraint-dependencies`, `environments`, `conflicts`, `workspace`, `sources`, `managed`, `package`, `default-groups`, `dev-dependencies`, `build-backend`
     "###
     );
 

docs/reference/settings.md

@@ -457,6 +457,42 @@ globs are interpreted as relative to the project directory.
 
 ---
 
+### [`check-url`](#check-url) {: #check-url }
+
+Check an index URL for existing files to skip duplicate uploads.
+
+This option allows retrying publishing that failed after only some, but not all files have
+been uploaded, and handles error due to parallel uploads of the same file.
+
+Before uploading, the index is checked. If the exact same file already exists in the index,
+the file will not be uploaded. If an error occurred during the upload, the index is checked
+again, to handle cases where the identical file was uploaded twice in parallel.
+
+The exact behavior will vary based on the index. When uploading to PyPI, uploading the same
+file succeeds even without `--check-url`, while most other indexes error.
+
+The index must provide one of the supported hashes (SHA-256, SHA-384, or SHA-512).
+
+**Default value**: `None`
+
+**Type**: `str`
+
+**Example usage**:
+
+=== "pyproject.toml"
+
+    ```toml
+    [tool.uv]
+    check-url = "https://test.pypi.org/simple"
+    ```
+=== "uv.toml"
+
+    ```toml
+    check-url = "https://test.pypi.org/simple"
+    ```
+
+---
+
 ### [`compile-bytecode`](#compile-bytecode) {: #compile-bytecode }
 
 Compile Python files to bytecode after installation.