Cannot use 'prefix' and 'start' together

[moander]

When prefix and start is used as read options only prefix is considered.

Expected result is to get rows b2 and b3.

Environment details

• @google-cloud/bigtable version: 0.15.0

Steps to reproduce

await bt.createTable('test4', {
    families: [
        'c'
    ]
}).catch(swallowCode(6));


bt.table('test4').mutate([
    {
        key: 'a1',
        method: 'insert',
        data: { c: { test: 1 } }
    },
    {
        key: 'a2',
        method: 'insert',
        data: { c: { test: 2 } }
    },
    {
        key: 'a3',
        method: 'insert',
        data: { c: { test: 3 } }
    },
    {
        key: 'b1',
        method: 'insert',
        data: { c: { test: 4 } }
    },
    {
        key: 'b2',
        method: 'insert',
        data: { c: { test: 5 } }
    },
    {
        key: 'b3',
        method: 'insert',
        data: { c: { test: 6 } }
    },
])

let [rows] = await bt.table('test4').getRows({
    prefix: 'b',
    start: 'b2',
});

console.log('got rows', rows.map(r => r.id));

// Result:
// got rows [ 'b1', 'b2', 'b3' ]

[moander]

This is weird. If you instead try the repro code using this mutation it will give you this result:

got rows [ 'b1', 'b2', 'b3', 'c1', 'c2', 'c3' ]

        bt.table('test4').mutate([
            {
                key: 'a1',
                method: 'insert',
                data: { c: { test: 1 } }
            },
            {
                key: 'a2',
                method: 'insert',
                data: { c: { test: 2 } }
            },
            {
                key: 'a3',
                method: 'insert',
                data: { c: { test: 3 } }
            },
            {
                key: 'b1',
                method: 'insert',
                data: { c: { test: 4 } }
            },
            {
                key: 'b2',
                method: 'insert',
                data: { c: { test: 5 } }
            },
            {
                key: 'b3',
                method: 'insert',
                data: { c: { test: 6 } }
            },
            {
                key: 'c1',
                method: 'insert',
                data: { c: { test: 4 } }
            },
            {
                key: 'c2',
                method: 'insert',
                data: { c: { test: 5 } }
            },
            {
                key: 'c3',
                method: 'insert',
                data: { c: { test: 6 } }
            },
        ])

[ajaaym]

can you try below? This should give you all row with prefix b starting from b2.

getRows({ start: 'b1', end: 'b' })

[moander]

@ajaaym that gives me the following error:

Error: 3 INVALID_ARGUMENT: Error in field 'row_ranges' : Error in element #0 : start_key must be less than end_key

[ajaaym]

Sorry there was a typo. Use end: ‘c’ instead of end: ‘b’.

[moander]

That won't help because I don't know the end in my actual code. I only know the prefix and the start key.

[ajaaym]

In that case you can use below.

let range = Table.createPrefixRange_(prefix);
range.start = 'b2';
getRows(range);

[sduskis]

I like ajaaym's solution. This also seems to work as intended. I don't think that we'll be doing more on this issue, unless there's a clear way forward.

[moander]

I disagree. The work around is fine but the implications here are huge.

Lets say you always use prefix´, but only sometimes you use start`. If the developer is not aware of this bug then he risks returning all the data from the table to the requestor.

[sduskis]

Perhaps we can throw an exception if both are set. WDYT?

[moander]

I can't use this library knowing you ignore reported security issues

[sduskis]

@moander, why do you think this is a security issue?

[sduskis]

For Cloud Bigtable clients, prefix and start/end are meant to be used independently. The Node.js API doesn't make that clear.

[sduskis]

There are four conflicting conditions that need to be exclusive:

• a set of ranges
• start / end
• prefix
• prefixes

There needs to be an exception if more than one of those conditions exist in the options, since there's no intuitive way to evaluate 2+ conditions.

[sduskis]

The exceptions were added in #315