fix(wrangler): fix build-env to exit with code rather than throw fa…

…tal error

Currently `pages functions build-env` throws a fatal
error if a config file does not exit, or if it is
invalid. This causes issues for the CI system. We
should instead exit with a specific code, if any of
those situations arises.

.changeset/green-rats-serve.md

@@ -0,0 +1,7 @@
+---
+"wrangler": minor
+---
+
+fix: fix `pages function build-env` to exit with code rather than throw fatal error
+
+Currently pages functions build-env throws a fatal error if a config file does not exit, or if it is invalid. This causes issues for the CI system. We should instead exit with a specific code, if any of those situations arises.

packages/wrangler/src/__tests__/pages/pages-build-env.test.ts

@@ -1,5 +1,9 @@
 /* eslint-disable turbo/no-undeclared-env-vars */
 import { readFileSync, writeFileSync } from "node:fs";
+import {
+	EXIT_CODE_INVALID_PAGES_CONFIG,
+	EXIT_CODE_NO_CONFIG_FOUND,
+} from "../../pages/errors";
 import { mockConsoleMethods } from "../helpers/mock-console";
 import { runInTempDir } from "../helpers/run-in-tmp";
 import { runWrangler } from "../helpers/run-wrangler";
@@ -33,26 +37,39 @@ describe("pages build env", () => {
 		);
 	});
 
-	it("should fail with no config file", async () => {
+	it("should exit with specific exit code if no config file is found", async () => {
+		const processExitMock = jest
+			.spyOn(process, "exit")
+			.mockImplementation(() => {
+				throw new Error("process exit mock");
+			});
 		await expect(
-			runWrangler("pages functions build-env . --outfile data.json")
-		).rejects.toThrowErrorMatchingInlineSnapshot(
-			`"No Pages config file found"`
-		);
+			runWrangler("pages functions build-env . --outfile out.json")
+		).rejects.toThrowErrorMatchingInlineSnapshot(`"process exit mock"`);
+		expect(processExitMock).toHaveBeenCalledWith(EXIT_CODE_NO_CONFIG_FOUND);
+		processExitMock.mockRestore();
 	});
+
 	it("should fail with no project dir", async () => {
 		await expect(
 			runWrangler("pages functions build-env")
 		).rejects.toThrowErrorMatchingInlineSnapshot(
 			`"No Pages project location specified"`
 		);
 	});
+
 	it("should fail with no outfile", async () => {
 		await expect(
 			runWrangler("pages functions build-env .")
 		).rejects.toThrowErrorMatchingInlineSnapshot(`"No outfile specified"`);
 	});
-	it("should fail correctly with a non-pages config file", async () => {
+
+	it("should exit with specific code if a non-pages config file is found", async () => {
+		const processExitMock = jest
+			.spyOn(process, "exit")
+			.mockImplementation(() => {
+				throw new Error("process exit mock");
+			});
 		writeWranglerToml({
 			vars: {
 				VAR1: "VALUE1",
@@ -81,21 +98,38 @@ describe("pages build env", () => {
 		// This error is specifically handled by the caller of build-env
 		await expect(
 			runWrangler("pages functions build-env . --outfile data.json")
-		).rejects.toThrowErrorMatchingInlineSnapshot(
-			`"Your wrangler.toml is not a valid Pages config file"`
+		).rejects.toThrowErrorMatchingInlineSnapshot(`"process exit mock"`);
+		expect(processExitMock).toHaveBeenCalledWith(
+			EXIT_CODE_INVALID_PAGES_CONFIG
 		);
+		processExitMock.mockRestore();
 	});
-	it("should fail correctly with an unparseable config file", async () => {
+
+	it("should exit correctly with an unparseable config file", async () => {
+		const processExitMock = jest
+			.spyOn(process, "exit")
+			.mockImplementation(() => {
+				throw new Error("process exit mock");
+			});
 		writeFileSync("./wrangler.toml", 'INVALID "FILE');
 		// This error is specifically handled by the caller of build-env
 		await expect(
 			runWrangler("pages functions build-env . --outfile data.json")
-		).rejects.toThrowErrorMatchingInlineSnapshot(
-			`"Your wrangler.toml is not a valid Pages config file"`
+		).rejects.toThrowErrorMatchingInlineSnapshot(`"process exit mock"`);
+		expect(processExitMock).toHaveBeenCalledWith(
+			EXIT_CODE_INVALID_PAGES_CONFIG
 		);
 		expect(std.err).toContain("ParseError");
+		processExitMock.mockRestore();
 	});
-	it("should fail correctly with a non-pages config file w/ invalid environment", async () => {
+
+	it("should exit correctly with a non-pages config file w/ invalid environment", async () => {
+		const processExitMock = jest
+			.spyOn(process, "exit")
+			.mockImplementation(() => {
+				throw new Error("process exit mock");
+			});
+
 		writeWranglerToml({
 			vars: {
 				VAR1: "VALUE1",
@@ -124,9 +158,11 @@ describe("pages build env", () => {
 		// This error is specifically handled by the caller of build-env
 		await expect(
 			runWrangler("pages functions build-env . --outfile data.json")
-		).rejects.toThrowErrorMatchingInlineSnapshot(
-			`"Your wrangler.toml is not a valid Pages config file"`
+		).rejects.toThrowErrorMatchingInlineSnapshot(`"process exit mock"`);
+		expect(processExitMock).toHaveBeenCalledWith(
+			EXIT_CODE_INVALID_PAGES_CONFIG
 		);
+		processExitMock.mockRestore();
 	});
 
 	it("should return top-level by default", async () => {
@@ -169,6 +205,7 @@ describe("pages build env", () => {
 			`"{\\"vars\\":{\\"VAR1\\":\\"VALUE1\\",\\"VAR2\\":\\"VALUE2\\"},\\"pages_build_output_dir\\":\\"dist\\"}"`
 		);
 	});
+
 	it("should return production", async () => {
 		process.env.PAGES_ENVIRONMENT = "production";
 		writeWranglerToml({

packages/wrangler/src/pages/build-env.ts

@@ -3,7 +3,11 @@ import path from "node:path";
 import { readConfig } from "../config";
 import { FatalError } from "../errors";
 import { logger } from "../logger";
-import { EXIT_CODE_NO_CONFIG_FOUND } from "./errors";
+import {
+	EXIT_CODE_INVALID_PAGES_CONFIG,
+	EXIT_CODE_NO_CONFIG_FOUND,
+} from "./errors";
+import type { Config } from "../config";
 import type {
 	CommonYargsArgv,
 	StrictYargsOptionsToInterface,
@@ -34,24 +38,30 @@ export const Handler = async (args: PagesBuildEnvArgs) => {
 	}
 
 	const configPath = path.resolve(args.projectDir, "wrangler.toml");
-	// Fail early if the config file doesn't exist
 	if (!existsSync(configPath)) {
-		throw new FatalError(
-			"No Pages config file found",
-			EXIT_CODE_NO_CONFIG_FOUND
-		);
+		logger.log("No Pages config file found. Skipping...");
+		process.exit(EXIT_CODE_NO_CONFIG_FOUND);
 	}
+
 	logger.log("Reading build configuration from your wrangler.toml file...");
 
-	const config = readConfig(
-		configPath,
-		{
-			...args,
-			// eslint-disable-next-line turbo/no-undeclared-env-vars
-			env: process.env.PAGES_ENVIRONMENT,
-		},
-		true
-	);
+	let config: Omit<Config, "pages_build_output_dir"> & {
+		pages_build_output_dir: string;
+	};
+	try {
+		config = readConfig(
+			configPath,
+			{
+				...args,
+				// eslint-disable-next-line turbo/no-undeclared-env-vars
+				env: process.env.PAGES_ENVIRONMENT,
+			},
+			true
+		);
+	} catch (err) {
+		logger.log("Invalid Pages config file found. Skipping...");
+		process.exit(EXIT_CODE_INVALID_PAGES_CONFIG);
+	}
 
 	// Ensure JSON variables are not included
 	const textVars = Object.fromEntries(