issue_comments: 419969570

It would be good to add a tests for these variables in: - The data_vars argument to the Dataset constructor (these objects should become data_vars, not coords) - The DataArray constructor. - Explicitly adding these variables: - With Dataset.__setitem__, Dataset.coords.__setitem__ and DataArray.coords.__setitem__ - When there are no existing variables matching the dimension name, and when a 1D index variable matching the dimension name already exists (the existing index should be deleted/cleared) - Converting these objects to pandas with to_dataframe, to_series and to_pandas - Concatenating along an existing dimension whose name matches existing variables (e.g., concatenate along x when a variable x with dimensions ('x', 'y') exists) - Concatenating along a new dimension whose name matches existing variables (e.g., concatenate along x when a variable x with dimensions ('y',) exists) - More generally, test variables where the name matches a dimension but the variable does not include that dimension at all, e.g., a variable 'x' with dimensions ('y',) in a Dataset where x is a dimension.