test: add test and mocked methods through utils object

Author: Ben Lmsc

tests/index.test.js

@@ -1,7 +1,25 @@
 const {onPreBuild} = require("./../index");
 
+const utils         = {
+  run   : {
+    command() {},
+  },
+  build : {
+    failBuild(message) {
+      throw new Error(message);
+    },
+  },
+  cache : {
+    save() {},
+    restore() {},
+  },
+  status: {
+    show() {},
+  },
+};
 const addProcessEnv = (...envVars) => { envVars.forEach(envVar => process.env[envVar] = `Test for ${envVar}`); };
-const preCallback   = (prefix, def) => onPreBuild({inputs: {prefix, def}});
+const preCallback   = (prefix, def) => onPreBuild({inputs: {prefix, def}, utils});
+
 
 test("normal configuration", () => {
   // Prepares data
@@ -22,7 +40,7 @@ test("normal configuration", () => {
   ));
 });
 
-test("fails to use env with no def argument, should throw error", () => {
+test("fails to use env with def no argument, should throw error", () => {
   // Prepares data
   const [prefix, def] = [
     "REACT_APP",
@@ -38,3 +56,20 @@ test("fails to use env with no def argument, should throw error", () => {
   // Checks if the error is correct
   expect(t).toThrow();
 });
+
+test("fails to use env with bad def argument, should throw error", () => {
+  // Prepares data
+  const [prefix, def] = [
+    "REACT_APP",
+    ["VAR_1", "VAR_2"],
+  ];
+
+  // adds the raw data to process env
+  addProcessEnv(...def);
+
+  // Prepares onPreBuild callback w/o def argument
+  const t = () => preCallback(prefix, 123);
+
+  // Checks if the error is correct
+  expect(t).toThrow();
+});