{
  "testCases": [{
    "description": "Modify scalar in a wrapper proto",
    "originalResource": {
      "wrapper": "a"
    },
    "modifiedResource": {
      "wrapper": "b"
    },
    "expectedMask": "wrapper"
  }, {
    "description": "Create wrapper proto",
    "originalResource": {
    },
    "modifiedResource": {
      "wrapper": "a"
    },
    "expectedMask": "wrapper"
  }, {
    "description": "Modify element in a repeated field",
    "originalResource": {
      "foos": [{
        "num": 1
      }, {
        "num": 2
      }]
    },
    "modifiedResource": {
      "foos": [{
        "num": 1
      }, {
        "num": 3
      }]
    },
    "expectedMask": "foos"
  }, {
    "description": "Modify element in a nested repeated field",
    "originalResource": {
      "foos": [{
        "bars": [{
          "num": 1
        }]
      }]
    },
    "modifiedResource": {
      "foos": [{
        "bars": [{
          "num": 2
        }]
      }]
    },
    "expectedMask": "foos"
  }, {
    "description": "Create submessage",
    "originalResource": {
    },
    "modifiedResource": {
      "foo": {
        "num": 1
      }
    },
    "expectedMask": "foo.num"
  }, {
    "description": "Modify submessage",
    "originalResource": {
      "foo": {
      }
    },
    "modifiedResource": {
      "foo": {
        "num": 1
      }
    },
    "expectedMask": "foo.num"
  }, {
    "description": "Clear submessage",
    "originalResource": {
      "foo": {
      }
    },
    "modifiedResource": {
    },
    "expectedMask": "foo"
  }, {
    "description": "No change",
    "originalResource": {
      "wrapper": "a",
      "foos": [{
        "num": 1
      }]
    },
    "modifiedResource": {
      "wrapper": "a",
      "foos": [{
        "num": 1
      }]
    },
    "expectedMask": ""
  }, {
    "description": "Create message with nested wrapper",
    "originalResource": {
    },
    "modifiedResource": {
      "foo": {
        "bar": {
          "nestedWrapper": true
        }
      }
    },
    "expectedMask": "foo.bar.nestedWrapper"
  }
]}