Allow making a schema to fail by returning an Err

schemars/tests/flatten.rs

@@ -1,6 +1,7 @@
 use pretty_assertions::assert_eq;
 use schemars::{schema_for, MakeSchema};
 use serde::{Deserialize, Serialize};
+use std::error::Error;
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, MakeSchema)]
 struct Flat {
@@ -32,6 +33,7 @@ struct Deep3 {
 
 #[test]
 #[ignore = "flattening is not yet implemented"]
-fn flatten_schema() {
-    assert_eq!(schema_for!(Flat), schema_for!(Deep1));
+fn flatten_schema() -> Result<(), Box<dyn Error>> {
+    assert_eq!(schema_for!(Flat)?, schema_for!(Deep1)?);
+    Ok(())
 }

schemars/tests/test.rs

@@ -3,13 +3,14 @@ use schemars::schema::*;
 use schemars::{gen, schema_for};
 use serde_json::{from_str, to_string_pretty};
 use std::fs;
+use std::error::Error;
 
 #[test]
-fn schema_matches_default_settings() -> Result<(), Box<dyn std::error::Error>> {
+fn schema_matches_default_settings() -> Result<(), Box<dyn Error>> {
     let expected_json = fs::read_to_string("tests/schema.json")?;
     let expected: Schema = from_str(&expected_json)?;
 
-    let actual = schema_for!(Schema);
+    let actual = schema_for!(Schema)?;
     fs::write("tests/schema.actual.json", to_string_pretty(&actual)?)?;
 
     assert_eq!(actual, expected, "Generated schema did not match saved schema - generated schema has been written to \"tests/schema.actual.json\".");
@@ -17,13 +18,13 @@ fn schema_matches_default_settings() -> Result<(), Box<dyn std::error::Error>> {
 }
 
 #[test]
-fn schema_matches_openapi3() -> Result<(), Box<dyn std::error::Error>> {
+fn schema_matches_openapi3() -> Result<(), Box<dyn Error>> {
     let expected_json = fs::read_to_string("tests/schema-openapi3.json")?;
     let expected: Schema = from_str(&expected_json)?;
 
     let actual = gen::SchemaSettings::openapi3()
         .into_generator()
-        .into_root_schema_for::<Schema>();
+        .into_root_schema_for::<Schema>()?;
     fs::write(
         "tests/schema-openapi3.actual.json",
         to_string_pretty(&actual)?,