fix(dedupeImports): respect negative and zero import priorities (#527)

8ctavio · antfu · web-flow · commit 4f462cb6c177 · 2026-04-22T10:53:30.000+09:00
* fix(dedupeImports): support negative import priorities * test(dedupeImports): consider imports' negative priorities * fix: apply @danielroe's fix --------- Co-authored-by: Anthony Fu <github@antfu.me>
diff --git a/src/utils.ts b/src/utils.ts
@@ -145,7 +145,7 @@ export function dedupeImports(imports: Import[], warn: (msg: string) => void) {
     if (isSameSpecifier) {
       if (Boolean(currImp.type) === Boolean(prevImp.type)) {
         // currImp and prevImp are the same import
-        if ((currImp.priority || 1) > (prevImp.priority || 1)) {
+        if ((currImp.priority ?? 1) > (prevImp.priority ?? 1)) {
           deduped.delete(name)
           deduped.set(name, currImp)
         }
@@ -157,7 +157,7 @@ export function dedupeImports(imports: Import[], warn: (msg: string) => void) {
         if (!prevImpComplement) {
           deduped.set(altName, currImp)
         }
-        else if ((currImp.priority || 1) > (prevImpComplement.priority || 1)) {
+        else if ((currImp.priority ?? 1) > (prevImpComplement.priority ?? 1)) {
           deduped.delete(altName)
           deduped.set(altName, currImp)
         }
@@ -168,7 +168,10 @@ export function dedupeImports(imports: Import[], warn: (msg: string) => void) {
     // currImp and prevImp are duplicate imports
     const altName = encodeImportName(name)
     const prevImpComplement = deduped.get(altName)
-    const priorityDiff = (currImp.priority || 1) - Math.max(prevImp.priority || 1, prevImpComplement?.priority || 1)
+    const prevPriority = prevImpComplement
+      ? Math.max(prevImp.priority ?? 1, prevImpComplement.priority ?? 1)
+      : prevImp.priority ?? 1
+    const priorityDiff = (currImp.priority ?? 1) - prevPriority
     if (priorityDiff > 0) {
       deduped.delete(name)
       deduped.delete(altName)
diff --git a/test/dedupe.test.ts b/test/dedupe.test.ts
@@ -67,6 +67,58 @@ describe('dedupeImports', () => {
     `)
   })
 
+  it('should respect negative priority', () => {
+    expect(dedupeImports(
+      [
+        {
+          name: 'foo',
+          from: 'module1',
+        },
+        {
+          name: 'foo',
+          from: 'module2',
+          priority: -1,
+        },
+      ],
+      warnFn,
+    )).toMatchInlineSnapshot(`
+      [
+        {
+          "from": "module1",
+          "name": "foo",
+        },
+      ]
+    `)
+
+    expect(warnMsg).toMatchInlineSnapshot(`""`)
+  })
+
+  it('should treat priority 0 as lower than default', () => {
+    expect(dedupeImports(
+      [
+        {
+          name: 'foo',
+          from: 'module1',
+        },
+        {
+          name: 'foo',
+          from: 'module2',
+          priority: 0,
+        },
+      ],
+      warnFn,
+    )).toMatchInlineSnapshot(`
+      [
+        {
+          "from": "module1",
+          "name": "foo",
+        },
+      ]
+    `)
+
+    expect(warnMsg).toMatchInlineSnapshot(`""`)
+  })
+
   it('should not dedupe disabled imports', () => {
     const imports = [
       {
