allow to figure out, whether the Point.Builder has any fields

[kub]

since the build mehtod contains validation for fields emptiness, there should be also way, how to figure out, whether the Builder contains any fields (to prevent the build method from throwing an exception)

[codecov-io]

Codecov Report

Merging #434 into master will increase coverage by 0.01%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master     #434      +/-   ##
============================================
+ Coverage     85.93%   85.94%   +0.01%     
  Complexity      292      292              
============================================
  Files            20       20              
  Lines          1258     1259       +1     
  Branches        131      132       +1     
============================================
+ Hits           1081     1082       +1     
  Misses          116      116              
  Partials         61       61

Impacted Files	Coverage Δ	Complexity Δ
src/main/java/org/influxdb/dto/Point.java	82.92% <100%> (+0.1%)	31 <0> (ø)	⬇️

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[majst01]

What exact problem are you trying to solve, can you show it in a testcase ? Dont see the point actually.

[kub]

I'll try to explain my problem more into the detail, hope it helps:
as the Point is constructed by the Point.Builder, Point.Builder#build() can be called in different part of the application (different method), than Point.Builder#addField. In such case, there is no way how to avoid IllegalArgumentException, that is thrown from here in case, that no fields were actually added (e.g. because data of these fields was null).

It's also convenient for other cases. Imagine e.g. this one:

void reportValues(String value1, String value2, String value3) {
    def builder = Point.measurement(measurement).tag(tags).time(time)

    if(value1 != null) {
        builder.addField(TIMESERIES_1, value1)
    }

    if(value2 != null) {
        builder.addField(TIMESERIES_2, value2)
    }

    if(value3 != null) {
        builder.addField(TIMESERIES_3, value3)
    }

    builder.build() // throws IllegalArgumentException, if all values are null

}

... again - there should be a way, how to 'ask' the builder, whether it is ok, to call the build method or whether it will fail with the IllegalArgumentException.

[majst01]

Ok understood, but then you need to add a testcase and a addition to the usage description in the README.md to you MR.

[kub]

I've added unit test

I'm not sure about README.md - do you really think, that this small detail should be really added there? Tried to read through it and honestly - I'm not sure where to put it. Also seems to me, that README.md should not go into that level of detail (just for sake of readability) - what do you think?