feat: use branch prerelease property for detection

lib/is-prerelease.js

@@ -1,3 +1,11 @@
-export default function isPrerelease({ type, main }) {
-  return type === "prerelease" || (type === "release" && !main);
+export default function isPrerelease({ type, main, prerelease }) {
+  if (prerelease === false) {
+    return false;
+  }
+  return (
+    type === "prerelease" ||
+    (type === "release" && !main) ||
+    typeof prerelease == "string" ||
+    prerelease === true
+  );
 }

test/is-prerelease.test.js

@@ -0,0 +1,52 @@
+import test from "ava";
+import isPrerelease from "../lib/is-prerelease.js";
+
+test("Test for empty object", (t) => {
+  const branch = {};
+  t.is(isPrerelease(branch), false);
+});
+
+test("Test if prerelease true property as boolean is used correctly", (t) => {
+  const branch = {
+    prerelease: true,
+  };
+  t.is(isPrerelease(branch), true);
+});
+
+test("Test if prerelease false property as boolean is used correctly", (t) => {
+  const branch = {
+    prerelease: false,
+  };
+  t.is(isPrerelease(branch), false);
+});
+
+test("Test if prerelease property as string is used correctly", (t) => {
+  const branch = {
+    prerelease: "rc",
+  };
+  t.is(isPrerelease(branch), true);
+});
+
+test("Test if prerelease type is used correctly", (t) => {
+  const branch = {
+    type: "prerelease",
+  };
+  t.is(isPrerelease(branch), true);
+});
+
+test("Test if prerelease type and main is used correctly", (t) => {
+  const branch = {
+    type: "release",
+    main: false,
+  };
+  t.is(isPrerelease(branch), true);
+});
+
+test("Test if prerelease type and main in addition to prerelease is used correctly", (t) => {
+  const branch = {
+    type: "release",
+    main: false,
+    prerelease: false,
+  };
+  t.is(isPrerelease(branch), false);
+});