feat: allow the use of environment variables instead of CLI args

README.md

@@ -129,16 +129,16 @@ An interface to a deployed Step Function, with a function to execute a Step Func
 ### Arguments
 
 - When running tests with `jest` using `sls-test-tools` matchers there are certain parameters needed for `sls-test-tools` to make assertions.
-- These are passed as command line arguments, using quotation to match `jests` convention on test arguments.
+- These are passed either as command line arguments, using quotation to match `jests` convention on test arguments, or by using environment variables. CLI arguments override environment variables.
 
 **Required**
 
-- `'--stack=my-service-dev'` - the CloudFormation stack name of the stack under test.
+- `'--stack=my-service-dev'` or `process.env.CFN_STACK_NAME` - the CloudFormation stack name of the stack under test.
 
 **Optional**
 
-- `'--profile=[PROFILE NAME]'` (will default to `default`)
-- `'--region=[AWS Region]'` (will default to `eu-west-2`)
+- `'--profile=[PROFILE NAME]'` or `process.env.AWS_PROFILE` (will default to `default`)
+- `'--region=[AWS Region]'` or `process.env.AWS_REGION` (will default to `eu-west-2`)
 - `'--keep=true'` - keeps testing resources up to avoid creation throttles (e.g. SQS Queue created for EventBridge assertions)
 
 - To avoid issues we recommend `--runInBand`

package.json

@@ -28,14 +28,16 @@
   },
   "dependencies": {
     "aws-sdk": "^2.711.0",
-    "import-all.macro": "^3.1.0"
+    "import-all.macro": "^3.1.0",
+    "yargs": "^17.3.1"
   },
   "devDependencies": {
     "@babel/cli": "^7.16.0",
     "@babel/core": "^7.16.0",
     "@babel/plugin-transform-runtime": "^7.16.0",
     "@babel/preset-env": "^7.16.0",
     "@babel/preset-typescript": "^7.16.0",
+    "@types/yargs": "^17.0.8",
     "@typescript-eslint/eslint-plugin": "^5.6.0",
     "@typescript-eslint/parser": "^5.6.0",
     "@zerollup/ts-transform-paths": "^1.7.18",

src/helpers/general.ts

@@ -1,14 +1,24 @@
 import AWS, { AWSError } from "aws-sdk";
 import { DescribeStacksOutput } from "aws-sdk/clients/cloudformation";
 import { PromiseResult } from "aws-sdk/lib/request";
-
-const profileArg = process.argv.filter((x) => x.startsWith("--profile="))[0];
-const profile = profileArg ? profileArg.split("=")[1] : "default";
-const stackArg = process.argv.filter((x) => x.startsWith("--stack="))[0];
-const regionArg = process.argv.filter((x) => x.startsWith("--region="))[0];
-export const region = regionArg ? regionArg.split("=")[1] : "eu-west-2";
-
-export const stackName = stackArg.split("=")[1];
+import { loadArg } from "./utils/loadArg";
+
+export const stackName = loadArg({
+  cliArg: "stack",
+  processEnvName: "CFN_STACK_NAME",
+});
+
+const profile = loadArg({
+  cliArg: "profile",
+  processEnvName: "AWS_PROFILE",
+  defaultValue: "default",
+});
+
+export const region = loadArg({
+  cliArg: "region",
+  processEnvName: "AWS_REGION",
+  defaultValue: "eu-west-2",
+});
 
 let creds;
 

src/helpers/utils/loadArg.ts

@@ -0,0 +1,36 @@
+import yargs from "yargs";
+
+const argv = yargs(process.argv).argv as Record<string, unknown>;
+
+const isNonEmptyString = (arg: unknown): arg is string =>
+  typeof arg === "string" && arg !== "";
+
+export const loadArg = ({
+  cliArg,
+  processEnvName,
+  defaultValue,
+}: {
+  cliArg: string;
+  processEnvName: string;
+  defaultValue?: string;
+}): string => {
+  let arg = argv[cliArg];
+
+  if (isNonEmptyString(arg)) {
+    return arg;
+  }
+
+  arg = process.env[processEnvName];
+
+  if (isNonEmptyString(arg)) {
+    return arg;
+  }
+
+  if (defaultValue === undefined) {
+    throw new Error(
+      `--${cliArg} CLI argument or ${processEnvName} env var required.`
+    );
+  }
+
+  return defaultValue;
+};

yarn.lock

@@ -1486,6 +1486,18 @@
   dependencies:
     "@types/node" "*"
 
+"@types/yargs-parser@*":
+  version "20.2.1"
+  resolved "https://registry.yarnpkg.com/@types/yargs-parser/-/yargs-parser-20.2.1.tgz#3b9ce2489919d9e4fea439b76916abc34b2df129"
+  integrity sha512-7tFImggNeNBVMsn0vLrpn1H1uPrUBdnARPTpZoitY37ZrdJREzf7I16tMrlK3hen349gr1NYh8CmZQa7CTG6Aw==
+
+"@types/yargs@^17.0.8":
+  version "17.0.8"
+  resolved "https://registry.yarnpkg.com/@types/yargs/-/yargs-17.0.8.tgz#d23a3476fd3da8a0ea44b5494ca7fa677b9dad4c"
+  integrity sha512-wDeUwiUmem9FzsyysEwRukaEdDNcwbROvQ9QGRKaLI6t+IltNzbn4/i4asmB10auvZGQCzSQ6t0GSczEThlUXw==
+  dependencies:
+    "@types/yargs-parser" "*"
+
 "@typescript-eslint/eslint-plugin@^5.6.0":
   version "5.7.0"
   resolved "https://registry.yarnpkg.com/@typescript-eslint/eslint-plugin/-/eslint-plugin-5.7.0.tgz#12d54709f8ea1da99a01d8a992cd0474ad0f0aa9"
@@ -6087,6 +6099,11 @@ yargs-parser@^18.1.2:
     camelcase "^5.0.0"
     decamelize "^1.2.0"
 
+yargs-parser@^21.0.0:
+  version "21.0.0"
+  resolved "https://registry.yarnpkg.com/yargs-parser/-/yargs-parser-21.0.0.tgz#a485d3966be4317426dd56bdb6a30131b281dc55"
+  integrity sha512-z9kApYUOCwoeZ78rfRYYWdiU/iNL6mwwYlkkZfJoyMR1xps+NEBX5X7XmRpxkZHhXJ6+Ey00IwKxBBSW9FIjyA==
+
 yargs@^15.0.2:
   version "15.4.1"
   resolved "https://registry.yarnpkg.com/yargs/-/yargs-15.4.1.tgz#0d87a16de01aee9d8bec2bfbf74f67851730f4f8"
@@ -6117,6 +6134,19 @@ yargs@^16.2.0:
     y18n "^5.0.5"
     yargs-parser "^20.2.2"
 
+yargs@^17.3.1:
+  version "17.3.1"
+  resolved "https://registry.yarnpkg.com/yargs/-/yargs-17.3.1.tgz#da56b28f32e2fd45aefb402ed9c26f42be4c07b9"
+  integrity sha512-WUANQeVgjLbNsEmGk20f+nlHgOqzRFpiGWVaBrYGYIGANIIu3lWjoyi0fNlFmJkvfhCZ6BXINe7/W2O2bV4iaA==
+  dependencies:
+    cliui "^7.0.2"
+    escalade "^3.1.1"
+    get-caller-file "^2.0.5"
+    require-directory "^2.1.1"
+    string-width "^4.2.3"
+    y18n "^5.0.5"
+    yargs-parser "^21.0.0"
+
 [email protected]:
   version "3.1.1"
   resolved "https://registry.yarnpkg.com/yn/-/yn-3.1.1.tgz#1e87401a09d767c1d5eab26a6e4c185182d2eb50"