feat: add $prepend and $append APIs to imports

src/helpers/vite.ts

@@ -61,7 +61,7 @@ export function addVitePlugin(
     insertPluginIntoConfig(plugin, config);
   }
 
-  magicast.imports.$add({
+  magicast.imports.$prepend({
     from: plugin.from,
     local: plugin.constructor,
     imported: plugin.imported || "default",

src/proxy/imports.ts

@@ -131,7 +131,11 @@
     return imports;
   };
 
-  const updateImport = (key: string, value: ImportItemInput) => {
+  const updateImport = (
+    key: string,
+    value: ImportItemInput,
+    order: "prepend" | "append",
+  ) => {
     const imports = getAllImports();
     const item = imports.find((i) => i.local === key);
     const local = value.local || key;
@@ -156,12 +160,20 @@
       (i) => i.from === value.from,
     )?.$declaration;
     if (declaration) {
-      // TODO: insert after the last import maybe?
       declaration.specifiers.push(specifier as any);
-    } else {
+    } else if (order === "prepend" || imports.length === 0) {
       root.body.unshift(
         b.importDeclaration([specifier], b.stringLiteral(value.from)) as any,
       );
+    } else {
+      // The `imports` length is already checked above, so `at(-1)` will exist
+      const lastImport = imports.at(-1)!.$declaration;
+      const lastImportIndex = root.body.indexOf(lastImport);
+      root.body.splice(
+        lastImportIndex + 1,
+        0,
+        b.importDeclaration([specifier], b.stringLiteral(value.from)) as any,
+      );
     }
     return true;
   };
@@ -185,7 +197,13 @@
     {
       $type: "imports",
       $add(item: ImportItemInput) {
-        proxy[item.local || item.imported] = item as any;
+        updateImport(item.local || item.imported, item, "prepend");
+      },
+      $prepend(item: ImportItemInput) {
+        updateImport(item.local || item.imported, item, "prepend");
+      },
+      $append(item: ImportItemInput) {
+        updateImport(item.local || item.imported, item, "append");
       },
       get $items() {
         return getAllImports();
@@ -203,7 +221,7 @@
         return getAllImports().find((i) => i.local === prop);
       },
       set(_, prop, value) {
-        return updateImport(prop as string, value);
+        return updateImport(prop as string, value, "prepend");
       },
       deleteProperty(_, prop) {
         return removeImport(prop as string);

src/proxy/types.ts

@@ -91,7 +91,10 @@ export type ProxifiedModule<T extends object = Record<string, any>> =
 export type ProxifiedImportsMap = Record<string, ProxifiedImportItem> &
   ProxyBase & {
     $type: "imports";
+    /** @deprecated Use `$prepend` instead  */
     $add: (item: ImportItemInput) => void;
+    $prepend: (item: ImportItemInput) => void;
+    $append: (item: ImportItemInput) => void;
     $items: ProxifiedImportItem[];
   };
 

test/function-call.test.ts

@@ -44,7 +44,7 @@ describe("function-calls", () => {
     const installVuePlugin = (mod: ProxifiedModule<any>) => {
       // Inject export default if not exists
       if (!mod.exports.default) {
-        mod.imports.$add({
+        mod.imports.$prepend({
           imported: "defineConfig",
           from: "vite",
         });
@@ -58,7 +58,7 @@ describe("function-calls", () => {
           : mod.exports.default;
 
       // Inject vue plugin import
-      mod.imports.$add({
+      mod.imports.$prepend({
         imported: "default",
         local: "vuePlugin",
         from: "@vitejs/plugin-vue",

test/imports.test.ts

@@ -84,28 +84,45 @@ foo: []
       });"
     `);
 
-    mod.imports.$add({
+    mod.imports.$prepend({
       from: "foo",
       imported: "default",
       local: "Foo",
     });
-    mod.imports.$add({
+    mod.imports.$prepend({
       from: "star",
       imported: "*",
       local: "Star",
     });
-    mod.imports.$add({
+    mod.imports.$prepend({
       from: "vite",
       imported: "Good",
     });
+    mod.imports.$append({
+      from: "append-foo",
+      imported: "default",
+      local: "AppendFoo",
+    });
+    mod.imports.$append({
+      from: "append-star",
+      imported: "*",
+      local: "AppendStar",
+    });
+    mod.imports.$append({
+      from: "vite",
+      imported: "AppendGood",
+    });
 
     expect(await generate(mod)).toMatchInlineSnapshot(`
       "import * as Star from "star";
       import Foo from "foo";
-      import { defineConfig, Good } from "vite";
+      import { defineConfig, Good, AppendGood } from "vite";
       import VuePlugin from "@vitejs/plugin-vue";
       import * as path2 from "path";
 
+      import AppendFoo from "append-foo";
+      import * as AppendStar from "append-star";
+
       export default defineConfig({
         foo: [],
       });"
@@ -117,10 +134,13 @@ foo: []
       "import { defineConfig } from "vitest/config";
       import * as Star from "star";
       import Foo from "foo";
-      import { Good } from "vite";
+      import { Good, AppendGood } from "vite";
       import VuePlugin from "@vitejs/plugin-vue";
       import * as path2 from "path";
 
+      import AppendFoo from "append-foo";
+      import * as AppendStar from "append-star";
+
       export default defineConfig({
         foo: [],
       });"