Check for external types

Author: djc

.github/workflows/ci.yml

@@ -66,3 +66,20 @@ jobs:
           persist-credentials: false
       - name: Check semver
         uses: obi1kenobi/cargo-semver-checks-action@v2
+
+  check-external-types:
+    name: Validate external types appearing in public API
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v5
+        with:
+          persist-credentials: false
+      - name: Install rust toolchain
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: nightly-2025-08-06
+          # ^ sync with https://github.com/awslabs/cargo-check-external-types/blob/main/rust-toolchain.toml
+      - run: cargo install --locked cargo-check-external-types
+      - name: run cargo-check-external-types
+        run: cargo check-external-types --all-features

Cargo.toml

@@ -53,3 +53,8 @@ no_individual_tags = true
 [package.metadata.docs.rs]
 rustdoc-args = ["--cfg", "docsrs"]
 all-features = true
+
+[package.metadata.cargo_check_external_types]
+allowed_external_types = [
+    "console", "console::*", "fuzzy_matcher::skim::SkimMatcherV2",
+]