Rust: add optional dependencies to ql tests

Also accept `options.yml` and `options.yaml` files as well for test options,
to get YAML syntax highlighting. In a follow up PR we might make the extension
mandatory.

rust/extractor/src/config.rs

@@ -43,6 +43,7 @@ pub struct Config {
     pub inputs: Vec<PathBuf>,
     pub qltest: bool,
     pub qltest_cargo_check: bool,
+    pub qltest_dependencies: Vec<String>,
 }
 
 impl Config {
@@ -61,7 +62,13 @@ impl Config {
                 .ancestors()
                 // only travel up while we're within the test pack
                 .take_while_inclusive(|p| !p.join("qlpack.yml").exists())
-                .map(|p| p.join("options"))
+                .flat_map(|p| {
+                    [
+                        p.join("options"),
+                        p.join("options.yml"),
+                        p.join("options.yaml"),
+                    ]
+                })
                 .filter(|p| p.exists())
                 .collect_vec();
             option_files.reverse();

rust/extractor/src/qltest.rs

@@ -21,7 +21,7 @@ fn dump_lib() -> anyhow::Result<()> {
     fs::write("lib.rs", lib).context("writing lib.rs")
 }
 
-fn dump_cargo_manifest() -> anyhow::Result<()> {
+fn dump_cargo_manifest(dependencies: &[String]) -> anyhow::Result<()> {
     let mut manifest = String::from(
         r#"[workspace]
 [package]
@@ -40,6 +40,13 @@ path = "main.rs"
 "#,
         );
     }
+    if !dependencies.is_empty() {
+        manifest.push_str("[dependencies]\n");
+        for dep in dependencies {
+            manifest.push_str(dep);
+            manifest.push('\n');
+        }
+    }
     fs::write("Cargo.toml", manifest).context("writing Cargo.toml")
 }
 
@@ -54,7 +61,7 @@ fn set_sources(config: &mut Config) -> anyhow::Result<()> {
 pub(crate) fn prepare(config: &mut Config) -> anyhow::Result<()> {
     dump_lib()?;
     set_sources(config)?;
-    dump_cargo_manifest()?;
+    dump_cargo_manifest(&config.qltest_dependencies)?;
     if config.qltest_cargo_check {
         let status = Command::new("cargo")
             .env("RUSTFLAGS", "-Awarnings")

rust/ql/integration-tests/qltest/dependencies/functions.expected

@@ -0,0 +1 @@
+| test.rs:4:1:7:1 | foo |

rust/ql/integration-tests/qltest/dependencies/functions.ql

@@ -0,0 +1,5 @@
+import rust
+
+from Function f
+where exists(f.getLocation().getFile().getRelativePath())
+select f

rust/ql/integration-tests/qltest/dependencies/options.yml

@@ -0,0 +1,4 @@
+qltest_cargo_check: true
+qltest_dependencies:
+    - anyhow = "1.0.86"
+    - log = "0.4.22"

rust/ql/integration-tests/qltest/dependencies/test.rs

@@ -0,0 +1,7 @@
+use anyhow;
+use log::info;
+
+fn foo() -> anyhow::Result<()> {
+    info!("logging works");
+    Ok(())
+}

rust/ql/integration-tests/qltest/test.py

@@ -1,17 +1,24 @@
 import runs_on
+import pytest
+
 # these tests are meant to exercise QL test running on multiple platforms
 # therefore they don't rely on integration test built-in QL test running
 # (which skips `qltest.{sh,cmd}`)
 
-def test_lib(codeql, rust, cwd):
-    codeql.test.run("lib", threads=1)
+@pytest.fixture(autouse=True)
+def default_options(codeql):
+    codeql.flags.update(
+        threads = 1,
+        show_extractor_output = True,
+        check_databases = False,
+    )
 
-def test_main(codeql, rust):
-    codeql.test.run("main", threads=1)
+@pytest.mark.parametrize("dir", ["lib", "main", "dependencies"])
+def test(codeql, rust, dir):
+    codeql.test.run(dir)
 
 def test_failing_cargo_check(codeql, rust):
-    out = codeql.test.run("failing_cargo_check", threads=1, show_extractor_output=True,
-                          _assert_failure=True, _capture="stderr")
+    out = codeql.test.run("failing_cargo_check", _assert_failure=True, _capture="stderr")
     # TODO: QL test output redirection is currently broken on windows, leaving it up for follow-up work
     if not runs_on.windows:
         assert "requested cargo check failed" in out