Add integration tests verifying lockfile stays current after release (#70)

Author: lukidoescode

.changeset/changesets/temptingly-supple-numbat.md

@@ -0,0 +1,4 @@
+---
+cargo-changeset: patch
+---
+Add integration tests verifying lockfile stays current after release

crates/cargo-changeset/tests/release_lockfile.rs

@@ -0,0 +1,200 @@
+use std::fs;
+use std::process::Command;
+
+use tempfile::TempDir;
+
+fn init_git_repo(dir: &TempDir) {
+    Command::new("git")
+        .args(["init", "--initial-branch=main"])
+        .current_dir(dir.path())
+        .output()
+        .expect("failed to init git repo");
+
+    Command::new("git")
+        .args(["config", "user.email", "test@example.com"])
+        .current_dir(dir.path())
+        .output()
+        .expect("failed to configure git email");
+
+    Command::new("git")
+        .args(["config", "user.name", "Test"])
+        .current_dir(dir.path())
+        .output()
+        .expect("failed to configure git name");
+}
+
+fn git_add_and_commit(dir: &TempDir, message: &str) {
+    Command::new("git")
+        .args(["add", "-A"])
+        .current_dir(dir.path())
+        .output()
+        .expect("failed to git add");
+
+    Command::new("git")
+        .args(["commit", "-m", message])
+        .current_dir(dir.path())
+        .output()
+        .expect("failed to git commit");
+}
+
+fn lockfile_hash(dir: &TempDir) -> Vec<u8> {
+    let output = Command::new("git")
+        .args(["hash-object", "Cargo.lock"])
+        .current_dir(dir.path())
+        .output()
+        .expect("failed to hash Cargo.lock");
+
+    output.stdout
+}
+
+fn write_changeset(dir: &TempDir, filename: &str, package: &str, bump: &str, summary: &str) {
+    let content = format!(
+        r#"---
+"{package}": {bump}
+---
+
+{summary}
+"#
+    );
+    fs::write(
+        dir.path().join(".changeset/changesets").join(filename),
+        content,
+    )
+    .expect("write changeset");
+}
+
+fn setup_workspace_with_dependency() -> TempDir {
+    let dir = TempDir::new().expect("create temp dir");
+
+    init_git_repo(&dir);
+
+    fs::write(
+        dir.path().join("Cargo.toml"),
+        r#"[workspace]
+members = ["crates/*"]
+resolver = "2"
+
+[workspace.dependencies]
+crate-a = { path = "crates/crate-a", version = "1.0.0" }
+"#,
+    )
+    .expect("write workspace Cargo.toml");
+
+    fs::create_dir_all(dir.path().join("crates/crate-a/src")).expect("create crate-a dir");
+    fs::write(
+        dir.path().join("crates/crate-a/Cargo.toml"),
+        r#"[package]
+name = "crate-a"
+version = "1.0.0"
+edition = "2021"
+"#,
+    )
+    .expect("write crate-a Cargo.toml");
+    fs::write(dir.path().join("crates/crate-a/src/lib.rs"), "").expect("write crate-a lib.rs");
+
+    fs::create_dir_all(dir.path().join("crates/crate-b/src")).expect("create crate-b dir");
+    fs::write(
+        dir.path().join("crates/crate-b/Cargo.toml"),
+        r#"[package]
+name = "crate-b"
+version = "2.0.0"
+edition = "2021"
+
+[dependencies]
+crate-a = { workspace = true }
+"#,
+    )
+    .expect("write crate-b Cargo.toml");
+    fs::write(dir.path().join("crates/crate-b/src/lib.rs"), "").expect("write crate-b lib.rs");
+
+    fs::create_dir_all(dir.path().join(".changeset/changesets"))
+        .expect("create .changeset/changesets dir");
+
+    let output = Command::new("cargo")
+        .args(["generate-lockfile"])
+        .current_dir(dir.path())
+        .output()
+        .expect("failed to run cargo generate-lockfile");
+    assert!(
+        output.status.success(),
+        "cargo generate-lockfile failed: {}",
+        String::from_utf8_lossy(&output.stderr)
+    );
+
+    git_add_and_commit(&dir, "Initial commit");
+
+    dir
+}
+
+macro_rules! cargo_changeset {
+    () => {
+        assert_cmd::cargo::cargo_bin_cmd!("cargo-changeset")
+    };
+}
+
+#[test]
+fn release_lockfile_not_dirtied_by_cargo_check() {
+    let workspace = setup_workspace_with_dependency();
+    write_changeset(&workspace, "fix.md", "crate-a", "patch", "Fix a bug");
+    git_add_and_commit(&workspace, "Add changeset");
+
+    cargo_changeset!()
+        .arg("release")
+        .current_dir(workspace.path())
+        .assert()
+        .success();
+
+    let hash_before = lockfile_hash(&workspace);
+
+    let check_output = Command::new("cargo")
+        .args(["check"])
+        .current_dir(workspace.path())
+        .output()
+        .expect("failed to run cargo check");
+    assert!(
+        check_output.status.success(),
+        "cargo check failed: {}",
+        String::from_utf8_lossy(&check_output.stderr)
+    );
+
+    let hash_after = lockfile_hash(&workspace);
+
+    assert_eq!(
+        hash_before, hash_after,
+        "cargo check should not change Cargo.lock after release — \
+         the release commit must include an up-to-date lockfile"
+    );
+}
+
+#[test]
+fn release_lockfile_correct_after_minor_bump_with_workspace_dep() {
+    let workspace = setup_workspace_with_dependency();
+    write_changeset(&workspace, "feat.md", "crate-a", "minor", "Add a feature");
+    git_add_and_commit(&workspace, "Add changeset");
+
+    cargo_changeset!()
+        .arg("release")
+        .current_dir(workspace.path())
+        .assert()
+        .success();
+
+    let hash_before = lockfile_hash(&workspace);
+
+    let check_output = Command::new("cargo")
+        .args(["check"])
+        .current_dir(workspace.path())
+        .output()
+        .expect("failed to run cargo check");
+    assert!(
+        check_output.status.success(),
+        "cargo check failed: {}",
+        String::from_utf8_lossy(&check_output.stderr)
+    );
+
+    let hash_after = lockfile_hash(&workspace);
+
+    assert_eq!(
+        hash_before, hash_after,
+        "cargo check should not change Cargo.lock after minor bump release"
+    );
+}