Import attributes should be enabled for node18 and >= node20 targets

[silverwind]

Import attributes were initially shipped in Node 21, but have recently been backported into 18 and 20 branches, specifically available in v21.0.0, v20.10.0, v18.20.0.

Ref: https://nodejs.org/api/esm.html#import-assertions

Current behaviour enables them only for node 21 and above:

$ echo "import foo from 'foo.json' with {type: 'json'}" | esbuild --target="node20"
import foo from "foo.json";
$ echo "import foo from 'foo.json' with {type: 'json'}" | esbuild --target="node21"
import foo from "foo.json" with { type: "json" };

[evanw]

Thanks for the heads up! I'll add support for node v18.20+.

Current behaviour enables them only for node 21 and above:

That's not exactly right. They're already enabled in v20.10+, just not v20+: (example)

[silverwind]

Thanks. I wasn't aware that target also accepts minor versions. Good to know.