i-slint-compiler: Add some tests for fileaccess

internal/compiler/fileaccess.rs

@@ -38,6 +38,44 @@ pub fn load_file(path: &std::path::Path) -> Option<VirtualFile> {
     }
 }
 
+#[test]
+fn test_load_file() {
+    let builtin = load_file(&std::path::PathBuf::from(
+        "builtin:/foo/../common/./MadeWithSlint-logo-dark.svg",
+    ))
+    .unwrap();
+    assert!(builtin.is_builtin());
+    assert_eq!(
+        builtin.canon_path,
+        std::path::PathBuf::from("builtin:/common/MadeWithSlint-logo-dark.svg")
+    );
+
+    let dir = std::env::var_os("CARGO_MANIFEST_DIR").unwrap().to_string_lossy().to_string();
+    let dir_path = std::path::PathBuf::from(dir);
+
+    let non_existing = dir_path.join("XXXCargo.tomlXXX");
+    assert!(load_file(&non_existing).is_none());
+
+    assert!(dir_path.exists()); // We need some existing path for all the rest
+
+    let cargo_toml = dir_path.join("Cargo.toml");
+    let abs_cargo_toml = load_file(&cargo_toml).unwrap();
+    assert!(!abs_cargo_toml.is_builtin());
+    assert!(crate::pathutils::is_absolute(&abs_cargo_toml.canon_path));
+    assert!(abs_cargo_toml.canon_path.exists());
+
+    let current = std::env::current_dir().unwrap();
+    assert!(current.ends_with("compiler")); // This test is run in .../internal/compiler
+
+    let cargo_toml = std::path::PathBuf::from("./tests/../Cargo.toml");
+    let rel_cargo_toml = load_file(&cargo_toml).unwrap();
+    assert!(!rel_cargo_toml.is_builtin());
+    assert!(crate::pathutils::is_absolute(&rel_cargo_toml.canon_path));
+    assert!(rel_cargo_toml.canon_path.exists());
+
+    assert_eq!(abs_cargo_toml.canon_path, rel_cargo_toml.canon_path);
+}
+
 mod builtin_library {
     include!(env!("SLINT_WIDGETS_LIBRARY"));