fix: detect object-valued conditions (#1243)

Co-Authored-By: Claude Opus 4.7

Author: tahmid-23

.changeset/stupid-ways-rush.md

@@ -0,0 +1,14 @@
+---
+"@opennextjs/cloudflare": patch
+---
+
+fix: detect object-valued conditions
+
+The pre-existing build condition transform logic had subtle errors:
+
+- failed to recognize object conditions
+  (e.g. "workerd": { "import": ..., "require": ... })
+- sibling pruning only applied to strings, not objects
+
+Now, we fully support object conditions. Furthermore, we prune siblings,
+unless its subtree also contains the build condition.

packages/cloudflare/src/cli/build/utils/workerd.spec.ts

@@ -59,10 +59,6 @@ describe("transformBuildCondition", () => {
 		expect(defaultExport.transformedExports).toEqual({
 			".": "/path/to/index.js",
 			"./server": {
-				"react-server": {
-					workerd: "./server.edge.js",
-					other: "./server.js",
-				},
 				default: "./server.js",
 			},
 		});
@@ -80,7 +76,7 @@ describe("transformBuildCondition", () => {
 		});
 	});
 
-	test("only consider leaves", () => {
+	test("object-valued condition", () => {
 		const exports = {
 			".": "/path/to/index.js",
 			"./server": {
@@ -92,7 +88,7 @@ describe("transformBuildCondition", () => {
 
 		const workerd = transformBuildCondition(exports, "workerd");
 
-		expect(workerd.hasBuildCondition).toBe(false);
+		expect(workerd.hasBuildCondition).toBe(true);
 		expect(workerd.transformedExports).toEqual({
 			".": "/path/to/index.js",
 			"./server": {
@@ -102,6 +98,25 @@ describe("transformBuildCondition", () => {
 			},
 		});
 	});
+
+	test("preserve sibling subtree that nests the condition", () => {
+		const exports = {
+			"react-server": {
+				workerd: "./rsc.edge.js",
+			},
+			workerd: "./top.edge.js",
+		};
+
+		const workerd = transformBuildCondition(exports, "workerd");
+
+		expect(workerd.hasBuildCondition).toBe(true);
+		expect(workerd.transformedExports).toEqual({
+			"react-server": {
+				workerd: "./rsc.edge.js",
+			},
+			workerd: "./top.edge.js",
+		});
+	});
 });
 
 describe("transformPackageJson", () => {
@@ -176,6 +191,38 @@ describe("transformPackageJson", () => {
 		expect(hasBuildCondition).toBe(true);
 	});
 
+	// https://github.com/opennextjs/opennextjs-cloudflare/issues/1153
+	// Matches the exports field of pg-cloudflare@1.3.0.
+	test("exports with object-valued workerd condition (pg-cloudflare)", () => {
+		const json = {
+			name: "pg-cloudflare",
+			exports: {
+				".": {
+					workerd: {
+						import: "./esm/index.mjs",
+						require: "./dist/index.js",
+					},
+					default: "./dist/empty.js",
+				},
+				"./package.json": "./package.json",
+			},
+		};
+		const { transformed, hasBuildCondition } = transformPackageJson(json);
+		expect(transformed).toEqual({
+			name: "pg-cloudflare",
+			exports: {
+				".": {
+					workerd: {
+						import: "./esm/index.mjs",
+						require: "./dist/index.js",
+					},
+				},
+				"./package.json": "./package.json",
+			},
+		});
+		expect(hasBuildCondition).toBe(true);
+	});
+
 	test("exports and imports with workerd condition both nested and top level", () => {
 		const json = {
 			name: "test",

packages/cloudflare/src/cli/build/utils/workerd.ts

@@ -23,27 +23,27 @@ export function transformBuildCondition(
 	hasBuildCondition: boolean;
 } {
 	const transformed: { [key: string]: unknown } = {};
-	const hasTopLevelBuildCondition = Object.keys(conditionMap).some(
-		(key) => key === condition && typeof conditionMap[key] === "string"
-	);
+	const hasTopLevelBuildCondition = condition in conditionMap && conditionMap[condition] != null;
 	let hasBuildCondition = hasTopLevelBuildCondition;
 	for (const [key, value] of Object.entries(conditionMap)) {
 		if (typeof value === "object" && value != null) {
 			const { transformedExports, hasBuildCondition: innerBuildCondition } = transformBuildCondition(
 				value as { [key: string]: unknown },
 				condition
 			);
+
+			// If a build condition is present at this level but a sibling
+			// subtree doesn't contain the build condition, we can drop it entirely.
+			if (hasTopLevelBuildCondition && key !== condition && !innerBuildCondition) {
+				continue;
+			}
+
 			transformed[key] = transformedExports;
 			hasBuildCondition ||= innerBuildCondition;
-		} else {
-			// If it doesn't have the build condition, we need to keep everything as is
-			// If it has the build condition, we need to keep only the build condition
-			// and remove everything else
-			if (!hasTopLevelBuildCondition) {
-				transformed[key] = value;
-			} else if (key === condition) {
-				transformed[key] = value;
-			}
+		} else if (!hasTopLevelBuildCondition || key === condition) {
+			// If there is no build condition at this level or this is a non-object build condition,
+			// we need to keep the child condition as is.
+			transformed[key] = value;
 		}
 	}
 	return { transformedExports: transformed, hasBuildCondition };