Use nan helpers to set exports

[richardlau]

Fixes compilation errors when built on Node.js master with V8 7.4.

Fixes: #116

[richardlau]

CI Node.js 6: https://ci.nodejs.org/view/post-mortem/job/nodereport-continuous-integration/297/ (✔️)
CI Node.js 8: https://ci.nodejs.org/view/post-mortem/job/nodereport-continuous-integration/298/ (✔️)
CI Node.js 10: https://ci.nodejs.org/view/post-mortem/job/nodereport-continuous-integration/299/ (✔️)
CI Node.js 11: https://ci.nodejs.org/view/post-mortem/job/nodereport-continuous-integration/300/ (✔️)
CI Node.js 12: https://ci.nodejs.org/view/post-mortem/job/nodereport-continuous-integration/301/ (✔️)

[sam-github]

Why'd you change the case of the method names?

[richardlau]

Why'd you change the case of the method names?

Because

  exports->Set(Nan::New("triggerReport").ToLocalChecked(),
               Nan::New<v8::FunctionTemplate>(TriggerReport)->GetFunction());

exports to JavaScript land a function called triggerReport (starting with a lower case letter) mapping to TriggerReport (the C++ method).

The replacement NAN_EXPORT(target, triggerReport); exports to JavaScript land a function with the same name as the C++ method so they must match case. Changing the case of the function exposed to JavaScript would be a semver major change (e.g. we document (https://github.com/nodejs/node-report#configuration) requiring 'node-report/api') so I changed the C++ side instead.

[sam-github]

mit: I suggest the commit message say why use of NAN_EXPORT() requires changing the function name.

[richardlau]

mit: I suggest the commit message say why use of NAN_EXPORT() requires changing the function name.

@sam-github How does the following sound?

NAN_EXPORT() requires the function name exported to JavaScript land and the exported C++ method to match. Change the exported C++ methods to begin with a lower case character to preserve the existing casing of the name exported to JavaScript.

[sam-github]

Very clear, thanks.