Respect #[serde(transparent)] attribute (#17)

schemars/tests/expected/transparent-struct.json

@@ -0,0 +1,33 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "OuterStruct",
+  "type": "object",
+  "properties": {
+    "inner": {
+      "anyOf": [
+        {
+          "$ref": "#/definitions/InnerStruct"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    }
+  },
+  "definitions": {
+    "InnerStruct": {
+      "type": "array",
+      "items": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "integer",
+          "format": "int32"
+        }
+      ],
+      "maxItems": 2,
+      "minItems": 2
+    }
+  }
+}

schemars/tests/transparent.rs

@@ -0,0 +1,27 @@
+mod util;
+use schemars::JsonSchema;
+use util::*;
+
+#[derive(Debug, JsonSchema)]
+pub struct OuterStruct {
+    inner: TransparentStruct,
+}
+
+#[derive(Debug, JsonSchema)]
+#[serde(transparent)]
+pub struct TransparentStruct {
+    #[serde(with = "TransparentNewType")]
+    inner: (),
+}
+
+#[derive(Debug, JsonSchema)]
+#[schemars(transparent)]
+pub struct TransparentNewType(Option<InnerStruct>);
+
+#[derive(Debug, JsonSchema)]
+pub struct InnerStruct(String, i32);
+
+#[test]
+fn transparent_struct() -> TestResult {
+    test_default_generated_schema::<OuterStruct>("transparent-struct")
+}