trustpub: Add cursor-based pagination to GitHub configs list endpoint (#12236)

Add cursor-based pagination to the `/api/v1/trusted_publishing/github_configs`
endpoint using the `id` field as the cursor. Pagination is always enabled with
a default of 10 items per page (following the codebase standard).

Key changes:
- Add `ListResponseMeta` with `total` and `next_page` fields
- Implement seek-based pagination ordered by `id` ascending
- Support `?per_page=N` (max 100) and `?seek=<encoded>` query parameters
- Optimize to avoid COUNT query when first page fits all results
- Add comprehensive pagination test covering multiple pages

The implementation follows existing pagination patterns from the versions
endpoint, using the `seek!()` macro for type-safe cursor serialization.

Author: Turbo87

src/controllers/trustpub/github_configs/json.rs

@@ -18,4 +18,18 @@ pub struct CreateResponse {
 #[derive(Debug, Serialize, utoipa::ToSchema)]
 pub struct ListResponse {
     pub github_configs: Vec<GitHubConfig>,
+
+    #[schema(inline)]
+    pub meta: ListResponseMeta,
+}
+
+#[derive(Debug, Serialize, utoipa::ToSchema)]
+pub struct ListResponseMeta {
+    /// The total number of GitHub configs belonging to the crate.
+    #[schema(example = 42)]
+    pub total: i64,
+
+    /// Query string to the next page of results, if any.
+    #[schema(example = "?seek=abc123")]
+    pub next_page: Option<String>,
 }

src/controllers/trustpub/github_configs/list/mod.rs

@@ -1,7 +1,11 @@
 use crate::app::AppState;
 use crate::auth::AuthCheck;
+use crate::controllers::helpers::pagination::{
+    Page, PaginationOptions, PaginationQueryParams, encode_seek,
+};
 use crate::controllers::krate::load_crate;
-use crate::controllers::trustpub::github_configs::json::{self, ListResponse};
+use crate::controllers::trustpub::github_configs::json::{self, ListResponse, ListResponseMeta};
+use crate::util::RequestUtils;
 use crate::util::errors::{AppResult, bad_request};
 use axum::Json;
 use axum::extract::{FromRequestParts, Query};
@@ -13,6 +17,7 @@ use diesel::dsl::{exists, select};
 use diesel::prelude::*;
 use diesel_async::RunQueryDsl;
 use http::request::Parts;
+use indexmap::IndexMap;
 use serde::Deserialize;
 
 #[derive(Debug, Deserialize, FromRequestParts, utoipa::IntoParams)]
@@ -28,7 +33,7 @@ pub struct ListQueryParams {
 #[utoipa::path(
     get,
     path = "/api/v1/trusted_publishing/github_configs",
-    params(ListQueryParams),
+    params(ListQueryParams, PaginationQueryParams),
     security(("cookie" = []), ("api_token" = [])),
     tag = "trusted_publishing",
     responses((status = 200, description = "Successful Response", body = inline(ListResponse))),
@@ -64,10 +69,13 @@ pub async fn list_trustpub_github_configs(
         return Err(bad_request("You are not an owner of this crate"));
     }
 
-    let configs = GitHubConfig::query()
-        .filter(trustpub_configs_github::crate_id.eq(krate.id))
-        .load(&mut conn)
-        .await?;
+    let pagination = PaginationOptions::builder()
+        .enable_seek(true)
+        .enable_pages(false)
+        .gather(&parts)?;
+
+    let (configs, total, next_page) =
+        list_configs(&mut conn, krate.id, &pagination, &parts).await?;
 
     let github_configs = configs
         .into_iter()
@@ -83,5 +91,91 @@ pub async fn list_trustpub_github_configs(
         })
         .collect();
 
-    Ok(Json(ListResponse { github_configs }))
+    Ok(Json(ListResponse {
+        github_configs,
+        meta: ListResponseMeta { total, next_page },
+    }))
+}
+
+async fn list_configs(
+    conn: &mut diesel_async::AsyncPgConnection,
+    crate_id: i32,
+    options: &PaginationOptions,
+    req: &Parts,
+) -> AppResult<(Vec<GitHubConfig>, i64, Option<String>)> {
+    use seek::*;
+
+    let seek = Seek::Id;
+
+    assert!(
+        !matches!(&options.page, Page::Numeric(_)),
+        "?page= is not supported"
+    );
+
+    let make_base_query = || {
+        GitHubConfig::query()
+            .filter(trustpub_configs_github::crate_id.eq(crate_id))
+            .into_boxed()
+    };
+
+    let mut query = make_base_query();
+    query = query.limit(options.per_page);
+    query = query.order(trustpub_configs_github::id.asc());
+
+    if let Some(SeekPayload::Id(Id { id })) = seek.after(&options.page)? {
+        query = query.filter(trustpub_configs_github::id.gt(id));
+    }
+
+    let data: Vec<GitHubConfig> = query.load(conn).await?;
+
+    let next_page = next_seek_params(&data, options, |last| seek.to_payload(last))?
+        .map(|p| req.query_with_params(p));
+
+    // Avoid the count query if we're on the first page and got fewer results than requested
+    let total =
+        if matches!(options.page, Page::Unspecified) && data.len() < options.per_page as usize {
+            data.len() as i64
+        } else {
+            make_base_query().count().get_result(conn).await?
+        };
+
+    Ok((data, total, next_page))
+}
+
+fn next_seek_params<T, S, F>(
+    records: &[T],
+    options: &PaginationOptions,
+    f: F,
+) -> AppResult<Option<IndexMap<String, String>>>
+where
+    F: Fn(&T) -> S,
+    S: serde::Serialize,
+{
+    if records.len() < options.per_page as usize {
+        return Ok(None);
+    }
+
+    let seek = f(records.last().unwrap());
+    let mut opts = IndexMap::new();
+    opts.insert("seek".into(), encode_seek(seek)?);
+    Ok(Some(opts))
+}
+
+mod seek {
+    use crate::controllers::helpers::pagination::seek;
+    use crates_io_database::models::trustpub::GitHubConfig;
+
+    seek!(
+        pub enum Seek {
+            Id { id: i32 },
+        }
+    );
+
+    impl Seek {
+        pub(crate) fn to_payload(&self, record: &GitHubConfig) -> SeekPayload {
+            match *self {
+                Seek::Id => SeekPayload::Id(Id { id: record.id }),
+            }
+        }
+    }
 }

src/tests/routes/trustpub/github_configs/list.rs

@@ -257,3 +257,67 @@ async fn test_token_auth_with_wildcard_crate_scope() -> anyhow::Result<()> {
 
     Ok(())
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_pagination() -> anyhow::Result<()> {
+    let (app, _, cookie_client) = TestApp::full().with_user().await;
+    let mut conn = app.db_conn().await;
+
+    let owner_id = cookie_client.as_model().id;
+    let krate = CrateBuilder::new("foo", owner_id).build(&mut conn).await?;
+
+    // Create 15 configs
+    for i in 0..15 {
+        create_config(&mut conn, krate.id, &format!("repo-{i}")).await?;
+    }
+
+    // Request first page with per_page=5
+    let response = cookie_client
+        .get_with_query::<()>(URL, "crate=foo&per_page=5")
+        .await;
+    assert_snapshot!(response.status(), @"200 OK");
+    let json = response.json();
+    assert_json_snapshot!(json, {
+        ".github_configs[].created_at" => "[datetime]",
+    });
+
+    // Extract the next_page URL and make a second request
+    let next_page = json["meta"]["next_page"]
+        .as_str()
+        .expect("next_page should be present");
+    let next_url = format!("{}{}", URL, next_page);
+    let response = cookie_client.get::<()>(&next_url).await;
+    assert_snapshot!(response.status(), @"200 OK");
+    let json = response.json();
+    assert_json_snapshot!(json, {
+        ".github_configs[].created_at" => "[datetime]",
+    });
+
+    // Third page (last page with data)
+    let next_page = json["meta"]["next_page"]
+        .as_str()
+        .expect("next_page should be present");
+    let next_url = format!("{}{}", URL, next_page);
+    let response = cookie_client.get::<()>(&next_url).await;
+    assert_snapshot!(response.status(), @"200 OK");
+    let json = response.json();
+    assert_json_snapshot!(json, {
+        ".github_configs[].created_at" => "[datetime]",
+    });
+
+    // The third page has exactly 5 items, so next_page will be present
+    // (cursor-based pagination is conservative about indicating more pages)
+    // Following it should give us an empty fourth page
+    let next_page = json["meta"]["next_page"]
+        .as_str()
+        .expect("next_page should be present on third page");
+    let next_url = format!("{}{}", URL, next_page);
+    let response = cookie_client.get::<()>(&next_url).await;
+    assert_snapshot!(response.status(), @"200 OK");
+    let json = response.json();
+    assert_json_snapshot!(json, {
+        ".github_configs[].created_at" => "[datetime]",
+    });
+
+    Ok(())
+}

src/tests/routes/trustpub/github_configs/snapshots/integration__routes__trustpub__github_configs__list__crate_with_no_configs-2.snap

@@ -3,5 +3,9 @@ source: src/tests/routes/trustpub/github_configs/list.rs
 expression: response.json()
 ---
 {
-  "github_configs": []
+  "github_configs": [],
+  "meta": {
+    "next_page": null,
+    "total": 0
+  }
 }

src/tests/routes/trustpub/github_configs/snapshots/integration__routes__trustpub__github_configs__list__happy_path-2.snap

@@ -24,5 +24,9 @@ expression: response.json()
       "repository_owner_id": 42,
       "workflow_filename": "publish.yml"
     }
-  ]
+  ],
+  "meta": {
+    "next_page": null,
+    "total": 2
+  }
 }

src/tests/routes/trustpub/github_configs/snapshots/integration__routes__trustpub__github_configs__list__happy_path-4.snap

@@ -14,5 +14,9 @@ expression: response.json()
       "repository_owner_id": 42,
       "workflow_filename": "publish.yml"
     }
-  ]
+  ],
+  "meta": {
+    "next_page": null,
+    "total": 1
+  }
 }

src/tests/routes/trustpub/github_configs/snapshots/integration__routes__trustpub__github_configs__list__legacy_token_auth-2.snap

@@ -14,5 +14,9 @@ expression: response.json()
       "repository_owner_id": 42,
       "workflow_filename": "publish.yml"
     }
-  ]
+  ],
+  "meta": {
+    "next_page": null,
+    "total": 1
+  }
 }

src/tests/routes/trustpub/github_configs/snapshots/integration__routes__trustpub__github_configs__list__pagination-2.snap

@@ -0,0 +1,62 @@
+---
+source: src/tests/routes/trustpub/github_configs/list.rs
+expression: json
+---
+{
+  "github_configs": [
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 1,
+      "repository_name": "repo-0",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    },
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 2,
+      "repository_name": "repo-1",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    },
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 3,
+      "repository_name": "repo-2",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    },
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 4,
+      "repository_name": "repo-3",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    },
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 5,
+      "repository_name": "repo-4",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    }
+  ],
+  "meta": {
+    "next_page": "?crate=foo&per_page=5&seek=NQ",
+    "total": 15
+  }
+}

src/tests/routes/trustpub/github_configs/snapshots/integration__routes__trustpub__github_configs__list__pagination-4.snap

@@ -0,0 +1,62 @@
+---
+source: src/tests/routes/trustpub/github_configs/list.rs
+expression: json
+---
+{
+  "github_configs": [
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 6,
+      "repository_name": "repo-5",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    },
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 7,
+      "repository_name": "repo-6",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    },
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 8,
+      "repository_name": "repo-7",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    },
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 9,
+      "repository_name": "repo-8",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    },
+    {
+      "crate": "foo",
+      "created_at": "[datetime]",
+      "environment": null,
+      "id": 10,
+      "repository_name": "repo-9",
+      "repository_owner": "rust-lang",
+      "repository_owner_id": 42,
+      "workflow_filename": "publish.yml"
+    }
+  ],
+  "meta": {
+    "next_page": "?crate=foo&per_page=5&seek=MTA",
+    "total": 15
+  }
+}