Add config for inline JSON Schema maps

docs/source-2.0/guides/model-translations/converting-to-openapi.rst

@@ -804,6 +804,26 @@ mapStrategy (``string``)
             }
         }
 
+.. _generate-openapi-jsonschema-setting-useInlineMaps:
+
+useInlineMaps (``boolean``)
+    Configures Smithy to generate ``map`` shapes inline instead of as
+    references. This is necessary for some code generators to distinguish
+    between ``maps`` and ``structure`` shapes when generating.
+
+    .. code-block:: json
+        :caption: smithy-build.json
+
+        {
+            "version": "1.0",
+            "plugins": {
+                "openapi": {
+                    "service": "example.weather#Weather",
+                    "useInlineMaps": true
+                }
+            }
+        }
+
 .. _generate-openapi-jsonschema-setting-schemaDocumentExtensions:
 
 schemaDocumentExtensions (``Map<String, any>``)

smithy-jsonschema/src/main/java/software/amazon/smithy/jsonschema/DefaultRefStrategy.java

@@ -148,6 +148,17 @@ public boolean isInlined(Shape shape) {
             return true;
         }
 
+        // Maps are not inlined by default, but can be if configured.
+        // Maps are usually not a generated type in programming languages,
+        // but JSON schema represents them as "object" types which code
+        // generators may not distinguish from converted structures.
+        //
+        // Some code generators, however, will treat inline "object" types
+        // as maps and referenced ones as structures.
+        if (shape.isMapShape() && config.getUseInlineMaps()) {
+            return true;
+        }
+
         // Strings with the enum trait are never inlined. This helps to ensure
         // that the name of an enum string can be round-tripped from
         // Smithy -> JSON Schema -> Smithy, helps OpenAPI code generators to

smithy-jsonschema/src/main/java/software/amazon/smithy/jsonschema/JsonSchemaConfig.java

@@ -115,6 +115,7 @@ public String toString() {
     private boolean disableDefaultValues = false;
     private boolean disableIntEnums = false;
     private boolean addReferenceDescriptions = false;
+    private boolean useInlineMaps = false;
 
     public JsonSchemaConfig() {
         nodeMapper.setWhenMissingSetter(NodeMapper.WhenMissing.IGNORE);
@@ -479,4 +480,26 @@ public boolean getAddReferenceDescriptions() {
     public void setAddReferenceDescriptions(boolean addReferenceDescriptions) {
         this.addReferenceDescriptions = addReferenceDescriptions;
     }
+
+    /**
+     * Whether to inline map shapes when creating JSON Schema object types
+     * from them.
+     *
+     * <p>Defaults to {@code false}.</p>
+     *
+     * @return Whether to inline map shapes in the resulting schema
+     */
+    public boolean getUseInlineMaps() {
+        return useInlineMaps;
+    }
+
+    /**
+     * Sets whether to inline map shapes when creating JSON schema object types
+     * from them.
+     *
+     * @param useInlineMaps Whether to inline map shapes in the resulting schema.
+     */
+    public void setUseInlineMaps(boolean useInlineMaps) {
+        this.useInlineMaps = useInlineMaps;
+    }
 }

smithy-jsonschema/src/test/java/software/amazon/smithy/jsonschema/JsonSchemaConverterTest.java

@@ -573,6 +573,32 @@ public void supportsMapPropertyNames() {
         assertThat(schema.getAdditionalProperties().get().getType().get(), equalTo("string"));
     }
 
+    @Test
+    public void supportsInlineMapPropertyNames() {
+        ShapeId shapeId = ShapeId.from("smithy.api#String");
+        StringShape string = StringShape.builder().id(shapeId).build();
+        MapShape map = MapShape.builder().id("a.b#Map").key(shapeId).value(shapeId).build();
+        StructureShape container = StructureShape.builder().id("a.b#Container").addMember("map", map.getId()).build();
+        Model model = Model.builder().addShapes(container, map, string).build();
+        JsonSchemaConfig config = new JsonSchemaConfig();
+        config.setUseInlineMaps(true);
+        SchemaDocument document = JsonSchemaConverter.builder()
+                .config(config)
+                .model(model)
+                .build()
+                .convertShape(container);
+        Schema schema = document.getRootSchema();
+
+        assertThat(schema.getProperties().containsKey("map"), equalTo(true));
+        Schema mapMember = schema.getProperties().get("map");
+        assertThat(mapMember.getRef().isPresent(), equalTo(false));
+        assertThat(mapMember.getType().get(), equalTo("object"));
+        assertTrue(mapMember.getPropertyNames().isPresent());
+        assertThat(mapMember.getPropertyNames().get().getType().get(), equalTo("string"));
+        assertTrue(mapMember.getAdditionalProperties().isPresent());
+        assertThat(mapMember.getAdditionalProperties().get().getType().get(), equalTo("string"));
+    }
+
     @Test
     public void supportsMapPatternProperties() {
         ShapeId shapeId = ShapeId.from("smithy.api#String");
@@ -596,6 +622,35 @@ public void supportsMapPatternProperties() {
         assertThat(schema.getPatternProperties().get(pattern).getType().get(), equalTo("string"));
     }
 
+    @Test
+    public void supportsInlineMapPatternProperties() {
+        ShapeId shapeId = ShapeId.from("smithy.api#String");
+        StringShape string = StringShape.builder().id(shapeId).build();
+        String pattern = "[a-z]{1,16}";
+        StringShape key = StringShape.builder().id("a.b#Key")
+                .addTrait(new PatternTrait(pattern)).build();
+        MapShape map = MapShape.builder().id("a.b#Map").key(key.getId()).value(shapeId).build();
+        StructureShape container = StructureShape.builder().id("a.b#Container").addMember("map", map.getId()).build();
+        Model model = Model.builder().addShapes(container, map, key, string).build();
+        JsonSchemaConfig config = new JsonSchemaConfig();
+        config.setUseInlineMaps(true);
+        config.setMapStrategy(JsonSchemaConfig.MapStrategy.PATTERN_PROPERTIES);
+        SchemaDocument document = JsonSchemaConverter.builder()
+                .config(config)
+                .model(model)
+                .build()
+                .convertShape(container);
+        Schema schema = document.getRootSchema();
+
+        assertThat(schema.getProperties().containsKey("map"), equalTo(true));
+        Schema mapMember = schema.getProperties().get("map");
+        assertThat(mapMember.getRef().isPresent(), equalTo(false));
+        assertThat(mapMember.getType().get(), equalTo("object"));
+        assertThat(mapMember.getPatternProperties().size(), equalTo(1));
+        assertTrue(mapMember.getPatternProperties().containsKey(pattern));
+        assertThat(mapMember.getPatternProperties().get(pattern).getType().get(), equalTo("string"));
+    }
+
     @Test
     public void supportsMapPatternPropertiesWithDefaultPattern() {
         ShapeId shapeId = ShapeId.from("smithy.api#String");