Add Null expression tests

[mapedraza]

#1440 (comment)

When posting a measure v with value Null to a group with the following attributes:

Expression

            active: [
                {
                    name: 'a',
                    type: 'Number',
                    expression: 'v'
                },
                {
                    name: 'b',
                    type: 'Number',
                    expression: 'v*3'
                },
                {
                    name: 'c',
                    type: 'Boolean',
                    expression: 'v==null'
                },
                {
                    name: 'd',
                    type: 'Text',
                    expression: "v?'no soy null':'soy null'"
                },
                {
                    name: 'e',
                    type: 'Text',
                    expression: "v==null?'soy null':'no soy null'"
                },
                {
                    name: 'f',
                    type: 'Text',
                    expression: "(v*3)==null?'soy null':'no soy null'"
                },
                {
                    name: 'g',
                    type: 'Boolean',
                    expression: 'v == undefined'
                }
            ]

Expectations

                    v: {
                        value: null,
                        type: 'Number'
                    },
                    b: {
                        value: 0,
                        type: 'Number'
                    },
                    c: {
                        value: true,
                        type: 'Boolean'
                    },
                    d: {
                        value: 'soy null',
                        type: 'Text'
                    },
                    e: {
                        value: 'soy null',
                        type: 'Text'
                    },
                    f: {
                        value: 'no soy null',
                        type: 'Text'
                    },
                    g: {
                        value: true,
                        type: 'Boolean'
                    }

[mapedraza]

Pending to validate if expectations are the expected

[mapedraza]

Added more cases after discussing with @mrutid and some other minor fixes

• With null values
• With null and skipValues
• Without values (NaN)
• Without values (NaN) and skipValues
• With explicitAttrs

[mapedraza]

Conclusions:

• case b (v*3)
  • For Null values, is always failing (treating Null as 0)
  • For NaN values, it works well, giving Null as response.
• case f ((v*3)==Null?'soy null':'no soy null') is always failing
• Using explicitAttrs acts as sending a measurement with null value

[AlvaroVega]

• For Null values, is always failing (treating Null as 0)
• case f ((v*3)==Null?'soy null':'no soy null') is always failing

Then these tests should fails in that expected values? Currently are passing.
I mean these tests should check expected values in each case.

[mapedraza]

• For Null values, is always failing (treating Null as 0)
• case f ((v*3)==Null?'soy null':'no soy null') is always failing

Then these tests should fails in that expected values? Currently are passing. I mean these tests should check expected values in each case.

Right now, tests are set with the real behaviour. This need to be fixed according the real expected value in a subsequent PR

[mapedraza]

overpassed by #1474