feat: add addEnvVar to Executor

src/lib/Components/Executors/exports/Executor.ts

@@ -18,7 +18,7 @@ export abstract class Executor<
 > implements Generable
 {
   resource_class: ResourceClass;
-  parameters?: ExecutableParameters;
+  parameters: ExecutableParameters;
 
   /**
    * @param resource_class - The resource class of the environment
@@ -29,7 +29,7 @@ export abstract class Executor<
     parameters?: Exclude<ExecutableParameters, 'resource_class'>,
   ) {
     this.resource_class = resource_class;
-    this.parameters = parameters;
+    this.parameters = parameters || {};
   }
   abstract get generableType(): GenerableType;
   abstract get executorLiteral(): ExecutorLiteral;
@@ -52,4 +52,25 @@ export abstract class Executor<
   ): ReusableExecutor {
     return new ReusableExecutor(name, this, parameters);
   }
+
+  /**
+   * Add an environment variable to the Executor.
+   * This will be set in plain-text via the exported config file.
+   * Consider using project-level environment variables or a context for sensitive information.
+   * @see {@link https://circleci.com/docs/env-vars}
+   * @example
+   * ```
+   * myExecutor.addEnvVar('MY_VAR', 'my value');
+   * ```
+   */
+  addEnvVar(name: string, value: string): this {
+    if (!this.parameters.environment) {
+      this.parameters.environment = {
+        [name]: value,
+      };
+    } else {
+      this.parameters.environment[name] = value;
+    }
+    return this;
+  }
 }

tests/Executor.test.ts

@@ -8,10 +8,24 @@ describe('Instantiate Docker Executor', () => {
     resource_class: 'medium',
   };
 
+  const dockerWithEnv = new CircleCI.executors.DockerExecutor('cimg/node:lts');
+  dockerWithEnv.addEnvVar('MY_VAR', 'my value');
+  const expectedShapeWithEnv = {
+    docker: [{ image: 'cimg/node:lts' }],
+    resource_class: 'medium',
+    environment: {
+      MY_VAR: 'my value',
+    },
+  };
+
   it('Should match the expected output', () => {
     expect(docker.generate()).toEqual(expectedShape);
   });
 
+  it('Should match the expected output with env var', () => {
+    expect(dockerWithEnv.generate()).toEqual(expectedShapeWithEnv);
+  });
+
   it('Docker executor should be instance of an Executor', () => {
     expect(docker instanceof CircleCI.executors.Executor).toBeTruthy();
   });