Merge pull request #57 from JupiterOne/generate-config

Generate instance config in mock context if instanceConfig option is not provided

Author: ctdio

CHANGELOG.md

@@ -8,6 +8,12 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Changed
+
+- If unable to create a config from environment variables,
+  `createMockExecutionContext` and `createMockStepExecutionContext` will now
+  generate a mock configuration for testing.
+
 ## 0.5.0 - 2020-04-20
 
 ### Added

docs/testing.md

@@ -101,24 +101,50 @@ If the `instanceConfig` option is not set, the SDK will read the
 `src/instanceConfigFields.json` and load in values from environment variables
 and the project's `.env` file if present.
 
+If unable to load a config from environment variables, the function will create
+a configuration with mock values based the types specified in
+`src/instanceConfigFields.json`.
+
+Example `instanceConfigFields.json` file:
+
+```json
+{
+  "apiKey": {
+    "type": "string"
+  }
+}
+```
+
 Usage:
 
 ```typescript
 // creates a simple execution context with a mocked
-// logger and instance without a configuration
-const simpleContext = createMockExecutionContext();
+// logger and an instance with mocked values
+const contextWithGeneratedConfig = createMockExecutionContext();
+/**
+ * Returns:
+ *
+ * {
+ *   logger: <mockLogger>,
+ *   instance: {...<local integration instance>, config: { apiKey: 'STRING_VALUE' } }
+ * }
+ */
+
+// constructs instance config using environment variables
+process.env.API_KEY = 'my-api-key';
+const contextWithConfigBuiltFromEnv = createMockExecutionContext();
 /**
  * Returns:
  *
  * {
  *   logger: <mockLogger>,
- *   instance: <local integration instance>
+ *   instance: {...<local integration instance>, config: { apiKey: 'my-api-key' } }
  * }
  */
 
 // creates an execution context with a mocked
 // logger and instance populated with the input config
-const contextWithInstanceConfig = createMockExecutionContext({
+const contextWithProvidedInstanceConfig = createMockExecutionContext({
   instanceConfig: {
     apiKey: 'test',
   },

src/__tests__/__fixtures__/instanceConfigWithoutEnv/src/instanceConfigFields.json

@@ -0,0 +1,10 @@
+{
+  "myBooleanConfig": {
+    "type": "boolean"
+  },
+  "myStringConfig": {
+    "type": "string"
+  },
+  "myTypelessConfig": {}
+}
+

src/testing/__tests__/context.test.ts

@@ -63,6 +63,20 @@ import {
           },
         });
       });
+
+      test('generates instance config with fake values if unable to populate config with env values', () => {
+        loadProjectStructure('instanceConfigWithoutEnv');
+
+        const { instance } = createContext();
+        expect(instance).toEqual({
+          ...LOCAL_INTEGRATION_INSTANCE,
+          config: {
+            myBooleanConfig: true,
+            myStringConfig: 'STRING_VALUE',
+            myTypelessConfig: 'STRING_VALUE',
+          },
+        });
+      });
     });
   },
 );

src/testing/context.ts

@@ -2,6 +2,8 @@ import {
   IntegrationInstance,
   IntegrationExecutionContext,
   IntegrationStepExecutionContext,
+  IntegrationInstanceConfigField,
+  IntegrationInstanceConfigFieldMap,
 } from '../framework';
 
 import { loadInstanceConfigFields } from '../framework/config';
@@ -41,9 +43,12 @@ export function createMockExecutionContext({
         // failed to load configuration, not end of the world
         // because this is only used in testing
         //
+        // For convenience, we will generate a config for the developer
+        //
         // this would generally only happen when a developer does not
         // have an .env file configured or when an integration's test suite
         // runs in CI
+        instance.config = generateInstanceConfig(configFields);
       }
     }
   }
@@ -70,3 +75,27 @@ export function createMockStepExecutionContext(
     jobState: createMockJobState(options),
   };
 }
+
+function generateInstanceConfig(
+  configFields: IntegrationInstanceConfigFieldMap,
+): IntegrationInstance['config'] {
+  return Object.entries(configFields).reduce(
+    (acc: IntegrationInstance['config'], [field, config]) => {
+      acc[field] = getInstanceConfigValueFromType(config);
+      return acc;
+    },
+    {},
+  );
+}
+
+function getInstanceConfigValueFromType(
+  config: IntegrationInstanceConfigField,
+) {
+  switch (config.type) {
+    case 'boolean':
+      return true;
+    case 'string':
+    default:
+      return 'STRING_VALUE';
+  }
+}