return json.Marshal(doc) } <del> // CreateMergePatch creates a merge patch as specified in http://tools.ietf.org/html/draft-ietf-appsawg-json-merge-patch-07 // // 'a' is original, 'b' is the modified document. Both are to be given as json encoded content. // The function will return a mergeable json document with differences from a to b. // // An error will be returned if any of the two documents are invalid. func CreateMergePatch(a, b []byte) ([]byte, error) { aI := map[string]interface{}{} bI := map[string]interface{}{} err := json.Unmarshal(a, &aI) </del> <ins> // resemblesJSONArray indicates whether the byte-slice "appears" to be // a JSON array or not. // False-positives are possible, as this function does not check the internal // structure of the array. It only checks that the outer syntax is present and // correct. func resemblesJSONArray(input []byte) bool { input = bytes.TrimSpace(input) hasPrefix := bytes.HasPrefix(input, []byte("[")) hasSuffix := bytes.HasSuffix(input, []byte("]")) return hasPrefix && hasSuffix } // CreateMergePatch will return a merge patch document capable of converting // the original document(s) to the modified document(s). // The parameters can be bytes of either two JSON Documents, or two arrays of // JSON documents. // The merge patch returned follows the specification defined at http://tools.ietf.org/html/draft-ietf-appsawg-json-merge-patch-07 func CreateMergePatch(originalJSON, modifiedJSON []byte) ([]byte, error) { originalResemblesArray := resemblesJSONArray(originalJSON) modifiedResemblesArray := resemblesJSONArray(modifiedJSON) // Do both byte-slices seem like JSON arrays? if originalResemblesArray && modifiedResemblesArray { return createArrayMergePatch(originalJSON, modifiedJSON) } // Are both byte-slices are not arrays? Then they are likely JSON objects... if !originalResemblesArray && !modifiedResemblesArray { return createObjectMergePatch(originalJSON, modifiedJSON) } // None of the above? Then return an error because of mismatched types. return nil, errBadMergeTypes } // createObjectMergePatch will return a merge-patch document capable of // converting the original document to the modified document. func createObjectMergePatch(originalJSON, modifiedJSON []byte) ([]byte, error) { originalDoc := map[string]interface{}{} modifiedDoc := map[string]interface{}{} err := json.Unmarshal(originalJSON, &originalDoc) </ins> if err != nil { return nil, errBadJSONDoc } <del> err = json.Unmarshal(b, &bI) </del> <ins> err = json.Unmarshal(modifiedJSON, &modifiedDoc) </ins> if err != nil { return nil, errBadJSONDoc } <del> dest, err := getDiff(aI, bI) </del> <ins> dest, err := getDiff(originalDoc, modifiedDoc) </ins> if err != nil { return nil, err } return json.Marshal(dest) } <ins> // createArrayMergePatch will return an array of merge-patch documents capable // of converting the original document to the modified document for each // pair of JSON documents provided in the arrays. // Arrays of mismatched sizes will result in an error. func createArrayMergePatch(originalJSON, modifiedJSON []byte) ([]byte, error) { originalDocs := []json.RawMessage{} modifiedDocs := []json.RawMessage{} err := json.Unmarshal(originalJSON, &originalDocs) if err != nil { return nil, errBadJSONDoc } err = json.Unmarshal(modifiedJSON, &modifiedDocs) if err != nil { return nil, errBadJSONDoc } total := len(originalDocs) if len(modifiedDocs) != total { return nil, errBadJSONDoc } result := []json.RawMessage{} for i := 0; i < len(originalDocs); i++ { original := originalDocs[i] modified := modifiedDocs[i] patch, err := createObjectMergePatch(original, modified) if err != nil { return nil, err } result = append(result, json.RawMessage(patch)) } return json.Marshal(result) } </ins> // Returns true if the array matches (must be json types). // As is idiomatic for go, an empty array is not the same as a nil array. func matchesArray(a, b []interface{}) bool {