Make _IdentityConverter compatible with Dart SDK 1.x

[aaronlademann-wf]

Problem

#17 was merged and released in version 2.1.0 without changing the lower-bound of the Dart SDK to >=2.0.0. The changes in #17 includes the construction of an _IdentityConverter instance without the new or const keyword, which is a Dart SDK 2.x-only feature.

This causes a regression for Dart 1.x SDK consumers building their application using the Dart Dev Compiler:

Error compiling dartdevc module:convert|lib/lib__convert.js

[error] '_IdentityConverter' isn't a function. (package:convert/src/identity_codec.dart, line 20, col 34)
[error] '_IdentityConverter' isn't a function. (package:convert/src/identity_codec.dart, line 21, col 34)

Solution

Use the new keyword to construct the instance. I attempted to keep it a const, but it does not appear that const constructors can have generic parameters using the Dart 1.x SDK.

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@jonasfj @kevmoo @lrhn @jayudey-wf @robbecker-wf

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[aaronlademann-wf]

@jonasfj @kevmoo @lrhn - the company I work for - (@Workiva) has signed the CLA.

[jonasfj]

@aaronlademann-wf, I dropped you a line by email to resolve the CLA issue. Hit me back if you need more help.

[greglittlefield-wf]

We just added Aaron to the correct group; he should have a valid CLA now.

[aaronlademann-wf]

@googlebot @jonasfj the CLA should be taken care of now.

[googlebot]

CLAs look good, thanks!

[kevmoo]

published!