Support #[serde(flatten)]ed structs

schemars/tests/flatten.rs

@@ -1,5 +1,5 @@
 use pretty_assertions::assert_eq;
-use schemars::{schema_for, MakeSchema};
+use schemars::{schema::*, schema_for, MakeSchema};
 use serde::{Deserialize, Serialize};
 use std::error::Error;
 
@@ -32,8 +32,13 @@ struct Deep3 {
 }
 
 #[test]
-#[ignore = "flattening is not yet implemented"]
 fn flatten_schema() -> Result<(), Box<dyn Error>> {
-    assert_eq!(schema_for!(Flat)?, schema_for!(Deep1)?);
+    let flat = schema_for!(Flat)?;
+    let mut deep = schema_for!(Deep1)?;
+    match deep {
+        Schema::Object(ref mut o) => o.title = Some("Flat".to_owned()),
+        _ => assert!(false, "Schema was not object: {:?}", deep),
+    };
+    assert_eq!(flat, deep);
     Ok(())
 }

schemars/tests/schema-openapi3.json

@@ -38,6 +38,7 @@
       ]
     },
     "SchemaObject": {
+      "type": "object",
       "properties": {
         "$id": {
           "type": "string",
@@ -76,10 +77,6 @@
           "items": {},
           "nullable": true
         },
-        "extensions": {
-          "type": "object",
-          "additionalProperties": true
-        },
         "items": {
           "anyOf": [
             {
@@ -125,8 +122,7 @@
           "type": "array",
           "items": {
             "type": "string"
-          },
-          "nullable": true
+          }
         },
         "title": {
           "type": "string",
@@ -146,9 +142,11 @@
           ],
           "nullable": true
         }
-      }
+      },
+      "additionalProperties": true
     },
     "SchemaRef": {
+      "type": "object",
       "properties": {
         "$ref": {
           "type": "string"

schemars/tests/schema.json

@@ -38,6 +38,7 @@
       ]
     },
     "SchemaObject": {
+      "type": "object",
       "properties": {
         "$id": {
           "anyOf": [
@@ -112,10 +113,6 @@
             }
           ]
         },
-        "extensions": {
-          "type": "object",
-          "additionalProperties": true
-        },
         "items": {
           "anyOf": [
             {
@@ -156,17 +153,10 @@
           }
         },
         "required": {
-          "anyOf": [
-            {
-              "type": "array",
-              "items": {
-                "type": "string"
-              }
-            },
-            {
-              "type": "null"
-            }
-          ]
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
         },
         "title": {
           "anyOf": [
@@ -188,9 +178,11 @@
             }
           ]
         }
-      }
+      },
+      "additionalProperties": true
     },
     "SchemaRef": {
+      "type": "object",
       "properties": {
         "$ref": {
           "type": "string"