Handle type + value importing better

This treats the first node as the "winner", so that our
"currentOwnerIsFirstImport" logic works correctly for comments at top of files

src/utils/__tests__/get-sorted-import-specifiers.spec.ts

@@ -31,7 +31,7 @@ test('should return correct sorted nodes with default import', () => {
     ]);
 });
 
-test('should group type imports after value imports', () => {
+test('should group type imports after value imports - typescript', () => {
     const code = `import Component, { type TypeB, filter, type TypeA, reduce, eventHandler } from '@server/z';`;
     const [importNode] = getImportNodes(code, {
         plugins: ['typescript'],
@@ -50,3 +50,23 @@ test('should group type imports after value imports', () => {
         'TypeB',
     ]);
 });
+
+test.only('should group type imports after value imports - flow', () => {
+    const code = `import Component, { type TypeB, filter, type TypeA, reduce, eventHandler } from '@server/z';`;
+    const [importNode] = getImportNodes(code, {
+        plugins: ['flow'],
+    });
+    const sortedImportSpecifiers = getSortedImportSpecifiers(importNode);
+    const specifiersList = getSortedNodesModulesNames(
+        sortedImportSpecifiers.specifiers,
+    );
+
+    expect(specifiersList).toEqual([
+        'Component',
+        'eventHandler',
+        'filter',
+        'reduce',
+        'TypeA',
+        'TypeB',
+    ]);
+});

src/utils/__tests__/merge-nodes-with-matching-flavors.spec.ts

@@ -61,7 +61,6 @@ import { Junk } from "junk-group-1";
 import "./side-effects1";
 
 // C, E and D will be separated from A, B because side-effects in-between
-
 import { D, type C, type E } from "a";
 
 // prettier-ignore

src/utils/get-sorted-import-specifiers.ts

@@ -22,7 +22,8 @@ export const getSortedImportSpecifiers = (node: ImportDeclaration) => {
             b.type === 'ImportSpecifier' &&
             a.importKind !== b.importKind
         ) {
-            return a.importKind === 'value' ? -1 : 1;
+            // flow uses null for value import specifiers
+            return a.importKind === 'value' || a.importKind == null ? -1 : 1;
         }
 
         return naturalSort(a.local.name, b.local.name);

src/utils/merge-nodes-with-matching-flavors.ts

@@ -135,14 +135,14 @@ function mergeIsSafe(
 /**
  * Mutates the modeToKeep, adding the import specifiers and comments from the nodeToForget.
  *
- * @returns (true to delete node | false to keep node)
+ * @returns (node to keep if we should delete the other node | null to keep everything)
  */
 function mergeNodes(
     nodeToKeep: ImportDeclaration,
     nodeToForget: ImportDeclaration,
 ) {
     if (!mergeIsSafe(nodeToKeep, nodeToForget)) {
-        return false;
+        return null;
     }
 
     if (
@@ -174,7 +174,7 @@ function mergeNodes(
         ...(nodeToForget.trailingComments || []),
     ];
 
-    return true;
+    return nodeToKeep;
 }
 
 /**
@@ -192,9 +192,26 @@ function mutateContextAndMerge({
     insertableNode: ImportDeclaration;
 }) {
     const source = selectNodeImportSource(insertableNode);
-    if (context[source]) {
-        if (mergeNodes(context[source], insertableNode)) {
-            nodesToDelete.push(insertableNode);
+    const existing = context[source];
+
+    if (existing) {
+        // Check if the existing is after the new one in the code.
+        // If so, we reverse the keep/delete so that the first node is kept.
+        // Important for top-of-file comment formatting.
+        if (
+            existing.start &&
+            insertableNode.start &&
+            existing.start > insertableNode.start
+        ) {
+            const merged = mergeNodes(insertableNode, existing);
+            if (merged) {
+                nodesToDelete.push(existing);
+                context[source] = merged;
+            }
+        } else {
+            if (mergeNodes(existing, insertableNode)) {
+                nodesToDelete.push(insertableNode);
+            }
         }
     } else {
         context[source] = insertableNode;

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

@@ -46,9 +46,7 @@ import { a } from 'a';
  */
 
 // second comment
-
-import { a, type A } from "a";
-// a
+import { a, type A } from "a"; // a
 import { b } from "b";
 
 `;