feat: support for arrays of mergeable objects in the “with” argument of “$merge”

.eslintrc.yml

@@ -12,7 +12,7 @@ rules:
   valid-jsdoc: [ 2, { requireReturn: false } ]
   no-invalid-this: 2
   no-unused-vars: [ 2, { args: none } ]
-  no-console: 2
+  no-console: 0
   block-scoped-var: 2
   complexity: [ 2, 9 ]
   curly: [ 2, multi-or-nest, consistent ]

keywords/generateMetaSchema.js

@@ -0,0 +1,28 @@
+'use strict';
+
+module.exports = function generateMetaSchema(patchSchema) {
+  return {
+    "type": "object",
+    "required": [ "source", "with" ],
+    "additionalProperties": false,
+    "properties": {
+      "source": {
+        "anyOf": [
+          {
+            "type": "object",
+            "required": [ "$ref" ],
+            "additionalProperties": false,
+            "properties": {
+              "$ref": {
+                "type": "string",
+                "format": "uri"
+              }
+            }
+          },
+          { "$ref": "http://json-schema.org/draft-06/schema#" }
+        ]
+      },
+      "with": patchSchema
+    }
+  };
+};

keywords/getSchema.js

@@ -0,0 +1,11 @@
+'use strict';
+
+var url = require('url');
+module.exports = function getSchema(ajv, it, $ref) {
+  var id = it.baseId && it.baseId != '#'
+            ? url.resolve(it.baseId, $ref)
+            : $ref;
+  var validate = ajv.getSchema(id);
+  if (validate) return validate.schema;
+  throw new ajv.constructor.MissingRefError(it.baseId, $ref);
+};

keywords/merge.js

@@ -1,8 +1,33 @@
 'use strict';
 
-var addKeyword = require('./add_keyword');
-var jsonMergePatch = require('json-merge-patch');
+var generateMetaSchema = require('./generateMetaSchema');
+var getSchema = require('./getSchema');
+var jsonPatch = require('json-merge-patch');
 
-module.exports = function(ajv) {
-  addKeyword(ajv, '$merge', jsonMergePatch, { "type": "object" });
+module.exports = function merge(ajv) {
+  ajv.addKeyword('$merge', {
+    macro: function (schema, parentSchema, it) {
+      var source = schema.source;
+      var patches = schema.with instanceof Array ? schema.with : [schema.with];
+      if (source.$ref) source = JSON.parse(JSON.stringify(getSchema(ajv, it, source.$ref)));
+      patches.forEach(function(patch) {
+        if (patch.$ref) patch = getSchema(ajv, it, patch.$ref);
+        jsonPatch.apply(source, patch, true);
+      });
+      return source;
+    },
+    metaSchema: generateMetaSchema({
+      "oneOf": [
+        {
+          "type": "object"
+        },
+        {
+          "type": "array",
+          "items": {
+            "type": "object"
+          }
+        }
+      ]
+    })
+  });
 };

keywords/patch.js

@@ -1,34 +1,45 @@
 'use strict';
 
-var addKeyword = require('./add_keyword');
+var generateMetaSchema = require('./generateMetaSchema');
+var getSchema = require('./getSchema');
 var jsonPatch = require('fast-json-patch/src/json-patch');
 
-module.exports = function(ajv) {
-  addKeyword(ajv, '$patch', jsonPatch, {
-    "type": "array",
-    "items": {
-      "type": "object",
-      "required": [ "op", "path" ],
-      "properties": {
-        "op": { "type": "string" },
-        "path": { "type": "string", "format": "json-pointer" }
-      },
-      "anyOf": [
-        {
-          "properties": { "op": { "enum": [ "add", "replace", "test" ] } },
-          "required": [ "value" ]
+module.exports = function (ajv) {
+  ajv.addKeyword('$patch', {
+    macro: function (schema, parentSchema, it) {
+      var source = schema.source;
+      var patch = schema.with;
+      if (source.$ref) source = JSON.parse(JSON.stringify(getSchema(ajv, it, source.$ref)));
+      if (patch.$ref) patch = getSchema(ajv, it, patch.$ref);
+      jsonPatch.applyPatch(source, patch, true);
+      return source;
+    },
+    metaSchema: generateMetaSchema({
+      "type": "array",
+      "items": {
+        "type": "object",
+        "required": [ "op", "path" ],
+        "properties": {
+          "op": { "type": "string" },
+          "path": { "type": "string", "format": "json-pointer" }
         },
-        {
-          "properties": { "op": { "enum": [ "remove" ] } }
-        },
-        {
-          "properties": {
-            "op": { "enum": [ "move", "copy" ] },
-            "from": { "type": "string", "format": "json-pointer" }
+        "anyOf": [
+          {
+            "properties": { "op": { "enum": [ "add", "replace", "test" ] } },
+            "required": [ "value" ]
+          },
+          {
+            "properties": { "op": { "enum": [ "remove" ] } }
           },
-          "required": [ "from" ]
-        }
-      ]
-    }
+          {
+            "properties": {
+              "op": { "enum": [ "move", "copy" ] },
+              "from": { "type": "string", "format": "json-pointer" }
+            },
+            "required": [ "from" ]
+          }
+        ]
+      }
+    })
   });
 };

spec/async.spec.js

@@ -20,7 +20,14 @@ describe('async schema loading', function() {
         "$merge": {
           "source": { "$ref": "obj.json#" },
           "with": {
-            "properties": { "q": { "type": "number" } }
+            "properties": {
+              "q": {
+                "type": "number"
+              },
+              "r": {
+                "type": "boolean"
+              }
+            }
           }
         }
       };
@@ -35,7 +42,8 @@ describe('async schema loading', function() {
         "$patch": {
           "source": { "$ref": "obj.json#" },
           "with": [
-            { "op": "add", "path": "/properties/q", "value": { "type": "number" } }
+            { "op": "add", "path": "/properties/q", "value": { "type": "number" } },
+            { "op": "add", "path": "/properties/r", "value": { "type": "boolean" } }
           ]
         }
       };

spec/errors.spec.js

@@ -18,7 +18,14 @@ describe('errors', function() {
         "$merge": {
           "source": { "$ref": "obj.json#" },
           "with": {
-            "properties": { "q": { "type": "number" } }
+            "properties": {
+              "q": {
+                "type": "number"
+              },
+              "r": {
+                "type": "boolean"
+              }
+            }
           }
         }
       };

spec/merge.spec.js

@@ -26,7 +26,14 @@ describe('keyword $merge', function() {
             "additionalProperties": false
           },
           "with": {
-            "properties": { "q": { "type": "number" } }
+            "properties": {
+              "q": {
+                "type": "number"
+              },
+              "r": {
+                "type": "boolean"
+              }
+            }
           }
         }
       };
@@ -53,7 +60,14 @@ describe('keyword $merge', function() {
         "$merge": {
           "source": { "$ref": "obj.json#" },
           "with": {
-            "properties": { "q": { "type": "number" } }
+            "properties": {
+              "q": {
+                "type": "number"
+              },
+              "r": {
+                "type": "boolean"
+              }
+            }
           }
         }
       };
@@ -79,7 +93,14 @@ describe('keyword $merge', function() {
         "$merge": {
           "source": { "$ref": "#/definitions/source" },
           "with": {
-            "properties": { "q": { "type": "number" } }
+            "properties": {
+              "q": {
+                "type": "number"
+              },
+              "r": {
+                "type": "boolean"
+              }
+            }
           }
         }
       };
@@ -101,7 +122,14 @@ describe('keyword $merge', function() {
 
       var patchSchema = {
         "type": "object",
-        "properties": { "q": { "type": "number" } },
+        "properties": {
+          "q": {
+            "type": "number"
+          },
+          "r": {
+            "type": "boolean"
+          }
+        },
         "additionalProperties": false
       };
 
@@ -137,7 +165,14 @@ describe('keyword $merge', function() {
         "definitions": {
           "patch":{
             "type": "object",
-            "properties": { "q": { "type": "number" } },
+            "properties": {
+              "q": {
+                "type": "number"
+              },
+              "r": {
+                "type": "boolean"
+              }
+            },
             "additionalProperties": false
           }
         },
@@ -151,4 +186,50 @@ describe('keyword $merge', function() {
       test(validate, '$merge');
     }
   });
+
+  it('should extend schema with an array of merging schemas', function() {
+    ajvInstances.forEach(testMerge);
+
+    function testMerge(ajv) {
+      var sourceSchema = {
+        "type": "object",
+        "properties": { "p": { "type": "string" } },
+        "additionalProperties": false
+      };
+
+      ajv.addSchema(sourceSchema, "obj1.json#");
+
+      var schema = {
+        "id": "obj2.json#",
+        "definitions": {
+          "patch":{
+            "type": "object",
+            "properties": {
+              "q": {
+                "type": "number"
+              }
+            },
+            "additionalProperties": false
+          }
+        },
+        "$merge": {
+          "source": { "$ref": "obj1.json#" },
+          "with": [
+            { "$ref": "#/definitions/patch" },
+            {
+              "type": "object",
+              "properties": {
+                "r": {
+                  "type": "boolean"
+                }
+              }
+            }
+          ]
+        }
+      };
+
+      var validate = ajv.compile(schema);
+      test(validate, '$merge');
+    }
+  });
 });