Json schema ref support (#1708)

* Add basic support for JSON schema $ref

* Add tests

2 files changed, 265 insertions, 2 deletions

diff --git a/ext/js/data/json-schema.js b/ext/js/data/json-schema.js
index bd6d9022..a6306c3a 100644
--- a/ext/js/data/json-schema.js
+++ b/ext/js/data/json-schema.js
@@ -25,6 +25,7 @@ class JsonSchema {
         this._startSchema = schema;
         this._rootSchema = typeof rootSchema !== 'undefined' ? rootSchema : schema;
         this._regexCache = null;
+        this._refCache = null;
         this._valueStack = [];
         this._schemaStack = [];
 
@@ -73,7 +74,8 @@ class JsonSchema {
     }
 
     getObjectPropertySchema(property) {
-        this._schemaPush(this._startSchema, null);
+        const startSchemaInfo = this._getResolveSchemaInfo({schema: this._startSchema, path: null});
+        this._schemaPush(startSchemaInfo.schema, startSchemaInfo.path);
         try {
             const schemaInfo = this._getObjectPropertySchemaInfo(property);
             return schemaInfo !== null ? new JsonSchema(schemaInfo.schema, this._rootSchema) : null;
@@ -83,7 +85,8 @@ class JsonSchema {
     }
 
     getArrayItemSchema(index) {
-        this._schemaPush(this._startSchema, null);
+        const startSchemaInfo = this._getResolveSchemaInfo({schema: this._startSchema, path: null});
+        this._schemaPush(startSchemaInfo.schema, startSchemaInfo.path);
         try {
             const schemaInfo = this._getArrayItemSchemaInfo(index);
             return schemaInfo !== null ? new JsonSchema(schemaInfo.schema, this._rootSchema) : null;
@@ -267,6 +270,71 @@ class JsonSchema {
         return value1 === value2;
     }
 
+    _getResolveSchemaInfo(schemaInfo) {
+        const ref = schemaInfo.schema.$ref;
+        if (typeof ref !== 'string') { return schemaInfo; }
+
+        const {path: basePath} = schemaInfo;
+        const {schema, path} = this._getReference(ref);
+        if (Array.isArray(basePath)) {
+            path.unshift(...basePath);
+        } else {
+            path.unshift(basePath);
+        }
+        return {schema, path};
+    }
+
+    _getReference(ref) {
+        if (!ref.startsWith('#/')) {
+            throw this._createError(`Unsupported reference path: ${ref}`);
+        }
+
+        let info;
+        if (this._refCache !== null) {
+            info = this._refCache.get(ref);
+        } else {
+            this._refCache = new Map();
+        }
+
+        if (typeof info === 'undefined') {
+            info = this._getReferenceUncached(ref);
+            this._refCache.set(ref, info);
+        }
+
+        return {schema: info.schema, path: [...info.path]};
+    }
+
+    _getReferenceUncached(ref) {
+        const visited = new Set();
+        const path = [];
+        while (true) {
+            if (visited.has(ref)) {
+                throw this._createError(`Recursive reference: ${ref}`);
+            }
+            visited.add(ref);
+
+            const pathParts = ref.substring(2).split('/');
+            let schema = this._rootSchema;
+            try {
+                for (const pathPart of pathParts) {
+                    schema = schema[pathPart];
+                }
+            } catch (e) {
+                throw this._createError(`Invalid reference: ${ref}`);
+            }
+            if (!this._isObject(schema)) {
+                throw this._createError(`Invalid reference: ${ref}`);
+            }
+
+            path.push(null, ...pathParts);
+
+            ref = schema.$ref;
+            if (typeof ref !== 'string') {
+                return {schema, path};
+            }
+        }
+    }
+
     // Validation
 
     _isValidCurrent(value) {
@@ -279,6 +347,22 @@ class JsonSchema {
     }
 
     _validate(value) {
+        const ref = this._schema.$ref;
+        const schemaInfo = (typeof ref === 'string') ? this._getReference(ref) : null;
+
+        if (schemaInfo === null) {
+            this._validateInner(value);
+        } else {
+            this._schemaPush(schemaInfo.schema, schemaInfo.path);
+            try {
+                this._validateInner(value);
+            } finally {
+                this._schemaPop();
+            }
+        }
+    }
+
+    _validateInner(value) {
         this._validateSingleSchema(value);
         this._validateConditional(value);
         this._validateAllOf(value);
@@ -638,6 +722,7 @@ class JsonSchema {
     }
 
     _getValidValueOrDefault(path, value, schemaInfo) {
+        schemaInfo = this._getResolveSchemaInfo(schemaInfo);
         this._schemaPush(schemaInfo.schema, schemaInfo.path);
         this._valuePush(value, path);
         try {
diff --git a/test/test-json-schema.js b/test/test-json-schema.js
index ba0131bf..c5ff830a 100644
--- a/test/test-json-schema.js
+++ b/test/test-json-schema.js
@@ -413,6 +413,80 @@ function testValidate2() {
                 {expected: false, value: []},
                 {expected: false, value: {}}
             ]
+        },
+
+        // Reference tests
+        {
+            schema: {
+                definitions: {
+                    example: {
+                        type: 'number'
+                    }
+                },
+                $ref: '#/definitions/example'
+            },
+            inputs: [
+                {expected: true,  value: 0},
+                {expected: true,  value: 0.5},
+                {expected: true,  value: 1},
+                {expected: false, value: '0'},
+                {expected: false, value: null},
+                {expected: false, value: []},
+                {expected: false, value: {}}
+            ]
+        },
+        {
+            schema: {
+                definitions: {
+                    example: {
+                        type: 'integer'
+                    }
+                },
+                $ref: '#/definitions/example'
+            },
+            inputs: [
+                {expected: true,  value: 0},
+                {expected: false, value: 0.5},
+                {expected: true,  value: 1},
+                {expected: false, value: '0'},
+                {expected: false, value: null},
+                {expected: false, value: []},
+                {expected: false, value: {}}
+            ]
+        },
+        {
+            schema: {
+                definitions: {
+                    example: {
+                        type: 'object',
+                        additionalProperties: false,
+                        properties: {
+                            test: {
+                                $ref: '#/definitions/example'
+                            }
+                        }
+                    }
+                },
+                $ref: '#/definitions/example'
+            },
+            inputs: [
+                {expected: false, value: 0},
+                {expected: false, value: 0.5},
+                {expected: false, value: 1},
+                {expected: false, value: '0'},
+                {expected: false, value: null},
+                {expected: false, value: []},
+                {expected: true,  value: {}},
+                {expected: false, value: {test: 0}},
+                {expected: false, value: {test: 0.5}},
+                {expected: false, value: {test: 1}},
+                {expected: false, value: {test: '0'}},
+                {expected: false, value: {test: null}},
+                {expected: false, value: {test: []}},
+                {expected: true,  value: {test: {}}},
+                {expected: true,  value: {test: {test: {}}}},
+                {expected: true,  value: {test: {test: {test: {}}}}}
+            ]
         }
     ];
 
@@ -690,6 +764,83 @@ function testGetValidValueOrDefault1() {
                     {test: -1}
                 ]
             ]
+        },
+
+        // Test references
+        {
+            schema: {
+                definitions: {
+                    example: {
+                        type: 'number',
+                        default: 0
+                    }
+                },
+                $ref: '#/definitions/example'
+            },
+            inputs: [
+                [
+                    1,
+                    1
+                ],
+                [
+                    null,
+                    0
+                ],
+                [
+                    'test',
+                    0
+                ],
+                [
+                    {test: 'value'},
+                    0
+                ]
+            ]
+        },
+        {
+            schema: {
+                definitions: {
+                    example: {
+                        type: 'object',
+                        additionalProperties: false,
+                        properties: {
+                            test: {
+                                $ref: '#/definitions/example'
+                            }
+                        }
+                    }
+                },
+                $ref: '#/definitions/example'
+            },
+            inputs: [
+                [
+                    1,
+                    {}
+                ],
+                [
+                    null,
+                    {}
+                ],
+                [
+                    'test',
+                    {}
+                ],
+                [
+                    {},
+                    {}
+                ],
+                [
+                    {test: {}},
+                    {test: {}}
+                ],
+                [
+                    {test: 'value'},
+                    {test: {}}
+                ],
+                [
+                    {test: {test: {}}},
+                    {test: {test: {}}}
+                ]
+            ]
         }
     ];
 
@@ -797,6 +948,33 @@ function testProxy1() {
                 {error: true,  value: ['default'], action: (value) => { delete value[0]; }},
                 {error: false, value: ['default'], action: (value) => { value[1] = 'string'; }}
             ]
+        },
+
+        // Reference tests
+        {
+            schema: {
+                definitions: {
+                    example: {
+                        type: 'object',
+                        additionalProperties: false,
+                        properties: {
+                            test: {
+                                $ref: '#/definitions/example'
+                            }
+                        }
+                    }
+                },
+                $ref: '#/definitions/example'
+            },
+            tests: [
+                {error: false, value: {}, action: (value) => { value.test = {}; }},
+                {error: false, value: {}, action: (value) => { value.test = {}; value.test.test = {}; }},
+                {error: false, value: {}, action: (value) => { value.test = {test: {}}; }},
+                {error: true,  value: {}, action: (value) => { value.test = null; }},
+                {error: true,  value: {}, action: (value) => { value.test = 'string'; }},
+                {error: true,  value: {}, action: (value) => { value.test = {}; value.test.test = 'string'; }},
+                {error: true,  value: {}, action: (value) => { value.test = {test: 'string'}; }}
+            ]
         }
     ];