chore: checkpoint before Python removal

vendor/schemars/tests/util/mod.rs

@@ -0,0 +1,42 @@
+use pretty_assertions::assert_eq;
+use schemars::{r#gen::SchemaSettings, schema::RootSchema, schema_for, JsonSchema};
+use std::error::Error;
+use std::fs;
+
+pub type TestResult = Result<(), Box<dyn Error>>;
+
+#[allow(dead_code)] // https://github.com/rust-lang/rust/issues/46379
+pub fn test_generated_schema<T: JsonSchema>(file: &str, settings: SchemaSettings) -> TestResult {
+    let actual = settings.into_generator().into_root_schema_for::<T>();
+    test_schema(&actual, file)
+}
+
+#[allow(dead_code)] // https://github.com/rust-lang/rust/issues/46379
+pub fn test_default_generated_schema<T: JsonSchema>(file: &str) -> TestResult {
+    let actual = schema_for!(T);
+    test_schema(&actual, file)
+}
+
+pub fn test_schema(actual: &RootSchema, file: &str) -> TestResult {
+    let expected_json = match fs::read_to_string(format!("tests/expected/{}.json", file)) {
+        Ok(j) => j,
+        Err(e) => {
+            write_actual_to_file(actual, file)?;
+            return Err(Box::from(e));
+        }
+    };
+    let expected = &serde_json::from_str(&expected_json)?;
+
+    if actual != expected {
+        write_actual_to_file(actual, file)?;
+    }
+
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+fn write_actual_to_file(schema: &RootSchema, file: &str) -> TestResult {
+    let actual_json = serde_json::to_string_pretty(&schema)?;
+    fs::write(format!("tests/actual/{}.json", file), actual_json)?;
+    Ok(())
+}