Skip uploads when validation reports 'Already uploaded'

crates/uv-publish/src/lib.rs

@@ -639,7 +639,9 @@ pub async fn upload(
     }
 }
 
-/// Validate a file against a registry.
+/// Validate a distribution before uploading.
+///
+/// Returns `true` if the file should be uploaded, `false` if it already exists on the server.
 pub async fn validate(
     file: &Path,
     form_metadata: &FormMetadata,
@@ -648,7 +650,7 @@ pub async fn validate(
     store: &PyxTokenStore,
     client: &BaseClient,
     credentials: &Credentials,
-) -> Result<(), PublishError> {
+) -> Result<bool, PublishError> {
     if store.is_known_url(registry) {
         debug!("Performing validation request for {registry}");
 
@@ -674,16 +676,45 @@ pub async fn validate(
             )
         })?;
 
+        let status_code = response.status();
+        debug!("Response code for {validation_url}: {status_code}");
+
+        if status_code.is_success() {
+            #[derive(Deserialize)]
+            struct ValidateResponse {
+                exists: bool,
+            }
+
+            // Check if the file already exists.
+            match response.text().await {
+                Ok(body) => {
+                    trace!("Response content for {validation_url}: {body}");
+                    if let Ok(response) = serde_json::from_str::<ValidateResponse>(&body) {
+                        if response.exists {
+                            debug!("File already uploaded: {raw_filename}");
+                            return Ok(false);
+                        }
+                    }
+                }
+                Err(err) => {
+                    trace!("Failed to read response content for {validation_url}: {err}");
+                }
+            }
+            return Ok(true);
+        }
+
+        // Handle error response.
         handle_response(&validation_url, response)
             .await
             .map_err(|err| {
                 PublishError::Validate(file.to_path_buf(), registry.clone().into(), err.into())
             })?;
+
+        Ok(true)
     } else {
         debug!("Skipping validation request for unsupported publish URL: {registry}");
+        Ok(true)
     }
-
-    Ok(())
 }
 
 /// Upload a file using the two-phase upload protocol for pyx.

crates/uv/src/commands/publish.rs

@@ -239,7 +239,7 @@ pub(crate) async fn publish(
         let uploaded = if direct {
             if dry_run {
                 // For dry run, call validate since we won't call reserve.
-                uv_publish::validate(
+                let should_upload = uv_publish::validate(
                     &group.file,
                     &form_metadata,
                     &group.raw_filename,
@@ -249,6 +249,13 @@ pub(crate) async fn publish(
                     &credentials,
                 )
                 .await?;
+                if !should_upload {
+                    writeln!(
+                        printer.stderr(),
+                        "{}",
+                        "File already exists, skipping".dimmed()
+                    )?;
+                }
                 continue;
             }
 
@@ -268,7 +275,7 @@ pub(crate) async fn publish(
             .await?
         } else {
             // Run validation checks on the file, but don't upload it (if possible).
-            uv_publish::validate(
+            let should_upload = uv_publish::validate(
                 &group.file,
                 &form_metadata,
                 &group.raw_filename,
@@ -283,20 +290,25 @@ pub(crate) async fn publish(
                 continue;
             }
 
-            let reporter = PublishReporter::single(printer);
-            upload(
-                &group,
-                &form_metadata,
-                &publish_url,
-                &upload_client,
-                retry_policy,
-                &credentials,
-                check_url_client.as_ref(),
-                &download_concurrency,
-                // Needs to be an `Arc` because the reqwest `Body` static lifetime requirement
-                Arc::new(reporter),
-            )
-            .await? // Filename and/or URL are already attached, if applicable.
+            // If validation indicates the file already exists, skip the upload.
+            if !should_upload {
+                false
+            } else {
+                let reporter = PublishReporter::single(printer);
+                upload(
+                    &group,
+                    &form_metadata,
+                    &publish_url,
+                    &upload_client,
+                    retry_policy,
+                    &credentials,
+                    check_url_client.as_ref(),
+                    &download_concurrency,
+                    // Needs to be an `Arc` because the reqwest `Body` static lifetime requirement
+                    Arc::new(reporter),
+                )
+                .await? // Filename and/or URL are already attached, if applicable.
+            }
         };
         info!("Upload succeeded");