3-way-merge

merge(o, a, b) -> c

3-way merging of JavaScript objects

Takes 3 versions of the same object -- where version 2 and 3 are both derived from version 1 -- and generates a 4th version, effectively merging version 2 and 3 together. When a conflict is detected (changes made in both version 2 and 3) changes from version 3 are used.

Prototype

merge(Object original, Object current, Object new) -> Object

• original: Ancestor version (original) from which both versionA and versionB are derived

• current: Version A of original

• new: Version B of original

Example:

// The original version which both A and B are derived from
original = {
    aliases: {
        abc: "Abc"
    },
    deleted: 7890,
    key: "string",
    list: [
        "abc",
        "def"
    ],
    value: 1234
}

// Version A
current = {
    aliases: {
        "abc": "Abcdef",
        "def": "Def"
    },
    list: [
        "abc",
        "cat",
        "def",
        "xyz"
    ],
    value: 123456
}

// Version B
B = {
    aliases: {
        abc: "Abc",
        aab: "Aab"
    },
    list: [
        "abc",
        "zzz"
    ],
    value: 1234
}

// --> Merged result
{
    aliases: {
        abc: "Abcdef",
        aab: "Aab",
        def: "Def"
    },
    list: [
        "abc",
        "cat",
        "xyz",
        "zzz"
    ],
    value: 123456
}

Requirements

• Array.isArray(object) -> Boolean to be implemented (which it is already in modern JavaScript environments)