Rust: add basic integration tests

This adds testing of well-formed rust projects and workspaces, using
both `Cargo.toml` and `rust-project.json` manifests.

Author: Paolo Tranquilli

rust/integration-tests/conftest.py

@@ -0,0 +1,15 @@
+import pytest
+import shutil
+
+class _Manifests:
+    def __init__(self, cwd):
+        self.dir = cwd / "manifests"
+
+    def select(self, name: str):
+        (self.dir / name).rename(name)
+        shutil.rmtree(self.dir)
+
+
+@pytest.fixture
+def manifests(cwd):
+    return _Manifests(cwd)

rust/integration-tests/hello-project/functions.expected

@@ -0,0 +1 @@
+| src/main.rs:4:1:6:1 | main |

rust/integration-tests/hello-project/functions.ql

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

rust/integration-tests/hello-project/manifests/Cargo.toml

@@ -0,0 +1,7 @@
+[workspace]
+[package]
+name = "hello-cargo"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

rust/integration-tests/hello-project/manifests/rust-project.json

@@ -0,0 +1,7 @@
+{
+  "crates": [{
+    "root_module": "src/main.rs",
+    "edition": "2021",
+    "deps": []
+  }]
+}

rust/integration-tests/hello-project/source_archive.expected

@@ -0,0 +1,4 @@
+src/directory_module/mod.rs
+src/directory_module/nested_module.rs
+src/file_module.rs
+src/main.rs

rust/integration-tests/hello-project/src/directory_module/ignored.rs

@@ -0,0 +1 @@
+mod nested_module;