Add support for import attributes (#174)

There are three styles of import assertions/attributes that have been
proposed over the years and made it to various stages of TC-39. Here's a
bit of
[history](https://github.com/tc39/proposal-import-attributes#history):

1) `import x from 'x' with type: "json"` - original proposal, made it to
stage 2
2) `import x from 'x' assert { type: 'json' };` - import "assertion",
got to stage 3, then found problems
3) `import x from 'x' with { type: 'json' };` - import "attribute",
current proposal, stage 3

Babel only supports these with the use of a parser plugin, either
`importAttributes` or `importAssertions`. Also, babel/generator has to
be told which style to generate. Upstream has a PR,
https://github.com/trivago/prettier-plugin-sort-imports/pull/273/files,
which adds another user-level option to control this. Instead, I've
taken the stance here that we should only generate the latest "import
attribute" style code. So, not only does this PR add support for import
attributes/assertions, this has the side-effect of converting deprecated
import assertions to import attributes. Maybe there's some reason
someone would want to stick with the old style, but I can't think of
one, and I personally would appreciate getting updated to the latest
format.

src/utils/__tests__/get-code-from-ast.spec.ts

@@ -71,3 +71,28 @@ import z from "z";
 `,
     );
 });
+
+test('handles import attributes and assertions, converting to attributes when necessary', async () => {
+    const code = `import z from 'z';
+    import g from 'g' with { type: 'json' };
+import c from 'c' assert { type: 'json' };
+`;
+    const importNodes = getImportNodes(code, {
+        plugins: [['importAttributes', { deprecatedAssertSyntax: true }]],
+    });
+    const sortedNodes = getSortedNodes(importNodes, {
+        importOrder: defaultImportOrder,
+        importOrderCombineTypeAndValueImports: true,
+    });
+    const formatted = getCodeFromAst({
+        nodesToOutput: sortedNodes,
+        originalCode: code,
+        directives: [],
+    });
+    expect(await format(formatted, { parser: 'babel' })).toEqual(
+        `import c from "c" with { type: "json" };
+import g from "g" with { type: "json" };
+import z from "z";
+`,
+    );
+});

src/utils/get-code-from-ast.ts

@@ -73,7 +73,7 @@ export const getCodeFromAst = ({
         },
     });
 
-    const { code } = generate(newAST);
+    const { code } = generate(newAST, { importAttributesKeyword: 'with' });
 
     const replacedCode = code.replace(injectNewlinesRegex, newLineCharacters);
 

tests/Babel/__snapshots__/ppsi.spec.ts.snap

@@ -1,5 +1,18 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
+exports[`imports-with-assertions.ts - babel-verify > imports-with-assertions.ts 1`] = `
+import z from 'z-assert' assert { type: 'json' };
+import x from 'x-with' with { type: 'json' };
+
+// import y from 'y-legacy' with type: "json" // <-- this format is from a very old proposal, and is not supported
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+import x from "x-with" with { type: "json" };
+import z from "z-assert" with { type: "json" };
+
+// import y from 'y-legacy' with type: "json" // <-- this format is from a very old proposal, and is not supported
+
+`;
+
 exports[`imports-with-comments.js - babel-verify > imports-with-comments.js 1`] = `
 // I am top level comment in this file.
 

tests/Babel/imports-with-assertions.ts

@@ -0,0 +1,4 @@
+import z from 'z-assert' assert { type: 'json' };
+import x from 'x-with' with { type: 'json' };
+
+// import y from 'y-legacy' with type: "json" // <-- this format is from a very old proposal, and is not supported

tests/Babel/ppsi.spec.ts

@@ -2,4 +2,5 @@ import {run_spec} from '../../test-setup/run_spec';
 
 run_spec(__dirname, ["babel"], {
     importOrder: [ "<THIRD_PARTY_MODULES>", '^@core/(.*)$', '^@server/(.*)', '^@ui/(.*)$', '^[./]'],
+    importOrderParserPlugins : ['[\"importAttributes\", {\"deprecatedAssertSyntax\": true}]'],
 });

tests/Typescript/__snapshots__/ppsi.spec.ts.snap

@@ -105,6 +105,19 @@ export class AppComponent extends BaseComponent {
 
 `;
 
+exports[`imports-with-assertions.ts - typescript-verify > imports-with-assertions.ts 1`] = `
+import z from 'z-assert' assert { type: 'json' };
+import x from 'x-with' with { type: 'json' };
+
+// import y from 'y-legacy' with type: "json" // <-- this format is from a very old proposal, and is not supported
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+import x from "x-with" with { type: "json" };
+import z from "z-assert" with { type: "json" };
+
+// import y from 'y-legacy' with type: "json" // <-- this format is from a very old proposal, and is not supported
+
+`;
+
 exports[`imports-with-comments.ts - typescript-verify > imports-with-comments.ts 1`] = `
 import z from 'z';
 import { isEmpty } from "lodash-es";

tests/Typescript/imports-with-assertions.ts

@@ -0,0 +1,4 @@
+import z from 'z-assert' assert { type: 'json' };
+import x from 'x-with' with { type: 'json' };
+
+// import y from 'y-legacy' with type: "json" // <-- this format is from a very old proposal, and is not supported

tests/Typescript/ppsi.spec.ts

@@ -2,5 +2,5 @@ import {run_spec} from '../../test-setup/run_spec';
 
 run_spec(__dirname, ["typescript"], {
     importOrder: ['^@core/(.*)$', '^@server/(.*)', '^@ui/(.*)$', '^[./]'],
-    importOrderParserPlugins : ['typescript', 'jsx', 'decorators-legacy', 'classProperties'],
+    importOrderParserPlugins : ['typescript', 'jsx', 'decorators-legacy', 'classProperties', '[\"importAttributes\", {\"deprecatedAssertSyntax\": true}]'],
 });