feat: support import attributes (#377)

The [Import Attributes
proposal](https://github.com/tc39/proposal-import-attributes) is in
Stage 3, so implementation is started. Currently, NFT bails on any file
that includes import attributes, because Acorn can't parse them. That's
because Acorn only supports Stage 4 proposals - but for import
attributes, there's a plugin that this PR adds to NFT.

package.json

@@ -21,6 +21,7 @@
     "@mapbox/node-pre-gyp": "^1.0.5",
     "@rollup/pluginutils": "^4.0.0",
     "acorn": "^8.6.0",
+    "acorn-import-attributes": "^1.9.2",
     "async-sema": "^3.1.1",
     "bindings": "^1.4.0",
     "estree-walker": "2.0.2",

src/analyze.ts

@@ -24,6 +24,7 @@ const acorn = Parser.extend(
   //require("acorn-class-fields"),
   //require("acorn-static-class-features"),
   //require("acorn-private-class-elements")
+  require("acorn-import-attributes").importAttributes
 );
 
 import os from 'os';

test/unit/import-attributes/info.json

@@ -0,0 +1,3 @@
+{
+  "foo": "bar"
+}

test/unit/import-attributes/input.js

@@ -0,0 +1,4 @@
+import foo from "./foo"
+import info from "./info.json" with { type: "json" }
+
+export default info

test/unit/import-attributes/output.js

@@ -0,0 +1,6 @@
+[
+  "package.json",
+  "test/unit/import-attributes/foo.js",
+  "test/unit/import-attributes/info.json",
+  "test/unit/import-attributes/input.js"
+]

yarn.lock

@@ -2596,6 +2596,11 @@ acorn-globals@^6.0.0:
     acorn "^7.1.1"
     acorn-walk "^7.1.1"
 
+acorn-import-attributes@^1.9.2:
+  version "1.9.2"
+  resolved "https://registry.yarnpkg.com/acorn-import-attributes/-/acorn-import-attributes-1.9.2.tgz#bc3765bca6ec0c5c69d2293afd582216215279b0"
+  integrity sha512-O+nfJwNolEA771IYJaiLWK1UAwjNsQmZbTRqqwBYxCgVQTmpFEMvBw6LOIQV0Me339L5UMVYFyRohGnGlQDdIQ==
+
 acorn-jsx@^5.3.2:
   version "5.3.2"
   resolved "https://registry.yarnpkg.com/acorn-jsx/-/acorn-jsx-5.3.2.tgz#7ed5bb55908b3b2f1bc55c6af1653bada7f07937"