1 files changed, 29 insertions, 0 deletions
diff --git a/graphs/js/jestBasic/fibo.js b/graphs/js/jestBasic/fibo.js
new file mode 100644
index 0000000..0a19955
--- /dev/null
+++ b/graphs/js/jestBasic/fibo.js
@@ -0,0 +1,29 @@
+function fibo(n) {
+    if (typeof n != "number" || isNaN(n)) {
+        return -1;
+    }
+
+    if (n < 0) {
+        return -1;
+    }
+
+    if (n === 0) {
+        return 0;
+    }
+
+    let a = 1;
+    let b = 1;
+    let result = 1;
+
+    for (let i = 2; i < n; i++) {
+        result = a + b;
+        b = a;
+        a = result;
+    }
+
+    return result;
+}
+
+module.exports = {
+    fibo,
+};