Skip creating env variables with undefined values

CHANGELOG.md

@@ -0,0 +1 @@
+- Fixes issue where `firebase functions:config:export` fails when an env value is `undefined`. (#7047)

src/functions/runtimeConfigExport.ts

@@ -19,7 +19,7 @@
 export interface EnvMap {
   origKey: string;
   newKey: string;
-  value: string;
+  value?: string;
   err?: string;
 }
 
@@ -81,7 +81,7 @@
       })
       .catch((err) => {
         logger.debug(
           `Failed to fetch runtime config for project ${info.projectId}: ${err.message}`,
         );
       });
   });
@@ -104,7 +104,7 @@
   let envKey = baseKey;
   try {
     env.validateKey(envKey);
   } catch (err: any) {
     if (err instanceof env.KeyValidationError) {
       envKey = prefix + envKey;
       env.validateKey(envKey);
@@ -123,19 +123,19 @@
   for (const [configKey, value] of flatten(configs)) {
     try {
       const envKey = convertKey(configKey, prefix);
       success.push({ origKey: configKey, newKey: envKey, value: value as string });
     } catch (err: any) {
       if (err instanceof env.KeyValidationError) {
         errors.push({
           origKey: configKey,
           newKey: err.key,
           err: err.message,
           value: value as string,
         });
       } else {
         throw new FirebaseError("Unexpected error while converting config", {
           exit: 2,
           original: err,
         });
       }
     }
@@ -144,14 +144,14 @@
 }
 
 /**
  * Fill in environment variables for each project by converting project's runtime config.
  *
  * @return {ConfigToEnvResult} Collection of successful and errored conversion.
  */
 export function hydrateEnvs(pInfos: ProjectConfigInfo[], prefix: string): string {
   let errMsg = "";
   for (const pInfo of pInfos) {
     const { success, errors } = configToEnv(pInfo.config!, prefix);
     if (errors.length > 0) {
       const msg =
         `${pInfo.projectId} ` +
@@ -185,11 +185,14 @@
  * Convert env var mapping to  dotenv compatible string.
  */
 export function toDotenvFormat(envs: EnvMap[], header = ""): string {
-  const lines = envs.map(({ newKey, value }) => `${newKey}="${escape(value)}"`);
+  const filteredEnvs = envs.filter((env) => env.value !== undefined);
+  const lines = filteredEnvs.map(({ newKey, value }) => `${newKey}="${escape(value!)}"`);
   const maxLineLen = Math.max(...lines.map((l) => l.length));
   return (
     `${header}\n` +
-    lines.map((line, idx) => `${line.padEnd(maxLineLen)} # from ${envs[idx].origKey}`).join("\n")
+    lines
+      .map((line, idx) => `${line.padEnd(maxLineLen)} # from ${filteredEnvs[idx].origKey}`)
+      .join("\n")
   );
 }
 

src/test/functions/runtimeConfigExport.spec.ts

@@ -131,6 +131,18 @@ describe("functions-config-export", () => {
       expect(errors).to.be.empty;
     });
 
+    it("should produce valid dotenv file with keys and skip undefined values", () => {
+      const dotenv = configExport.toDotenvFormat([
+        { origKey: "service.api.url", newKey: "SERVICE_API_URL", value: "hello" },
+        { origKey: "service.api.name", newKey: "SERVICE_API_NAME", value: undefined },
+      ]);
+      const { envs, errors } = env.parse(dotenv);
+      expect(envs).to.be.deep.equal({
+        SERVICE_API_URL: "hello",
+      });
+      expect(errors).to.be.empty;
+    });
+
     it("should preserve newline characters", () => {
       const dotenv = configExport.toDotenvFormat([
         { origKey: "service.api.url", newKey: "SERVICE_API_URL", value: "hello\nthere\nworld" },