Fix when missing functionConfig (#175)

Author: prachirp

ts/kpt-functions/package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "kpt-functions",
-  "version": "0.14.2",
+  "version": "0.14.3",
   "description": "KPT functions framework library",
   "author": "KPT Authors",
   "license": "Apache-2.0",

ts/kpt-functions/package.json

@@ -172,12 +172,10 @@ export class Configs {
    * Throws a FunctionConfigError if functionConfig is undefined OR
    * if the kind is not a v1/ConfigMap.
    */
-  getFunctionConfigMap() {
+  getFunctionConfigMap(): Map<string, string> | undefined {
     const cm = this.getFunctionConfig();
     if (cm === undefined) {
-      throw new FunctionConfigError(
-        `functionConfig expected, instead undefined`
-      );
+      return undefined;
     }
     if (!isConfigMap(cm)) {
       throw new FunctionConfigError(
@@ -204,7 +202,8 @@ export class Configs {
    * @key key The key in the 'data' field in the ConfigMap object given as the functionConfig.
    */
   getFunctionConfigValue(key: string): string | undefined {
-    return this.getFunctionConfigMap().get(key);
+    const cm = this.getFunctionConfigMap();
+    return cm ? cm.get(key) : cm;
   }
 
   /**

ts/kpt-functions/src/types.ts

@@ -264,8 +264,8 @@ describe('functionConfig', () => {
   it('no object', () => {
     const configs = new Configs(undefined);
     expect(configs.getFunctionConfig()).toBeUndefined();
-    expect(() => configs.getFunctionConfigMap()).toThrow();
-    expect(() => configs.getFunctionConfigValue('k3')).toThrow();
+    expect(configs.getFunctionConfigMap()).toBeUndefined();
+    expect(configs.getFunctionConfigValue('k3')).toBeUndefined();
     expect(() => configs.getFunctionConfigValueOrThrow('k3')).toThrow();
   });