From ba9fa2a7a09875f08fa90efc04146d8e8395e9b1 Mon Sep 17 00:00:00 2001 From: Nicolas Gallagher Date: Tue, 15 Mar 2016 11:34:09 -0700 Subject: [PATCH] [add] upstream 'merge' module --- src/modules/merge/index.js | 222 +++++++++++++++++++++++++++++++++++++ 1 file changed, 222 insertions(+) create mode 100644 src/modules/merge/index.js diff --git a/src/modules/merge/index.js b/src/modules/merge/index.js new file mode 100644 index 00000000..f1a268f3 --- /dev/null +++ b/src/modules/merge/index.js @@ -0,0 +1,222 @@ +/* eslint-disable */ +/** + * @generated SignedSource<> + * + * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + * !! This file is a check-in of a static_upstream project! !! + * !! !! + * !! You should not modify this file directly. Instead: !! + * !! 1) Use `fjs use-upstream` to temporarily replace this with !! + * !! the latest version from upstream. !! + * !! 2) Make your changes, test them, etc. !! + * !! 3) Use `fjs push-upstream` to copy your changes back to !! + * !! static_upstream. !! + * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + * + * Copyright 2013-2014 Facebook, Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * @providesModule mergeHelpers + * + * requiresPolyfills: Array.isArray + */ + +"use strict"; + +var invariant = require('fbjs/lib/invariant'); +var keyMirror = require('fbjs/lib/keyMirror'); + +/** + * Maximum number of levels to traverse. Will catch circular structures. + * @const + */ +var MAX_MERGE_DEPTH = 36; + +/** + * We won't worry about edge cases like new String('x') or new Boolean(true). + * Functions are considered terminals, and arrays are not. + * @param {*} o The item/object/value to test. + * @return {boolean} true iff the argument is a terminal. + */ +var isTerminal = function(o) { + return typeof o !== 'object' || o === null; +}; + +var mergeHelpers = { + + MAX_MERGE_DEPTH: MAX_MERGE_DEPTH, + + isTerminal: isTerminal, + + /** + * Converts null/undefined values into empty object. + * + * @param {?Object=} arg Argument to be normalized (nullable optional) + * @return {!Object} + */ + normalizeMergeArg: function(arg) { + return arg === undefined || arg === null ? {} : arg; + }, + + /** + * If merging Arrays, a merge strategy *must* be supplied. If not, it is + * likely the caller's fault. If this function is ever called with anything + * but `one` and `two` being `Array`s, it is the fault of the merge utilities. + * + * @param {*} one Array to merge into. + * @param {*} two Array to merge from. + */ + checkMergeArrayArgs: function(one, two) { + invariant( + Array.isArray(one) && Array.isArray(two), + 'Tried to merge arrays, instead got %s and %s.', + one, + two + ); + }, + + /** + * @param {*} one Object to merge into. + * @param {*} two Object to merge from. + */ + checkMergeObjectArgs: function(one, two) { + mergeHelpers.checkMergeObjectArg(one); + mergeHelpers.checkMergeObjectArg(two); + }, + + /** + * @param {*} arg + */ + checkMergeObjectArg: function(arg) { + invariant( + !isTerminal(arg) && !Array.isArray(arg), + 'Tried to merge an object, instead got %s.', + arg + ); + }, + + /** + * @param {*} arg + */ + checkMergeIntoObjectArg: function(arg) { + invariant( + (!isTerminal(arg) || typeof arg === 'function') && !Array.isArray(arg), + 'Tried to merge into an object, instead got %s.', + arg + ); + }, + + /** + * Checks that a merge was not given a circular object or an object that had + * too great of depth. + * + * @param {number} Level of recursion to validate against maximum. + */ + checkMergeLevel: function(level) { + invariant( + level < MAX_MERGE_DEPTH, + 'Maximum deep merge depth exceeded. You may be attempting to merge ' + + 'circular structures in an unsupported way.' + ); + }, + + /** + * Checks that the supplied merge strategy is valid. + * + * @param {string} Array merge strategy. + */ + checkArrayStrategy: function(strategy) { + invariant( + strategy === undefined || strategy in mergeHelpers.ArrayStrategies, + 'You must provide an array strategy to deep merge functions to ' + + 'instruct the deep merge how to resolve merging two arrays.' + ); + }, + + /** + * Set of possible behaviors of merge algorithms when encountering two Arrays + * that must be merged together. + * - `clobber`: The left `Array` is ignored. + * - `indexByIndex`: The result is achieved by recursively deep merging at + * each index. (not yet supported.) + */ + ArrayStrategies: keyMirror({ + Clobber: true, + IndexByIndex: true + }) + +}; + +/** + * @generated SignedSource<> + * + * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + * !! This file is a check-in of a static_upstream project! !! + * !! !! + * !! You should not modify this file directly. Instead: !! + * !! 1) Use `fjs use-upstream` to temporarily replace this with !! + * !! the latest version from upstream. !! + * !! 2) Make your changes, test them, etc. !! + * !! 3) Use `fjs push-upstream` to copy your changes back to !! + * !! static_upstream. !! + * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + * + * Copyright 2013-2014 Facebook, Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * @providesModule mergeInto + * @typechecks static-only + */ + +var checkMergeObjectArg = mergeHelpers.checkMergeObjectArg; +var checkMergeIntoObjectArg = mergeHelpers.checkMergeIntoObjectArg; + +/** + * Shallow merges two structures by mutating the first parameter. + * + * @param {object|function} one Object to be merged into. + * @param {?object} two Optional object with properties to merge from. + */ +function mergeInto(one, two) { + checkMergeIntoObjectArg(one); + if (two != null) { + checkMergeObjectArg(two); + for (var key in two) { + if (!two.hasOwnProperty(key)) { + continue; + } + one[key] = two[key]; + } + } +} + +var merge = function(one, two) { + var result = {}; + mergeInto(result, one); + mergeInto(result, two); + return result; +}; + +module.exports = merge;