From 1146d5ab7dd4f7eb4e5fc5f8f248737c293d880a Mon Sep 17 00:00:00 2001
From: Lumi Pakkanen <lumi.pakkanen@gmail.com>
Date: Thu, 8 Feb 2024 02:33:29 +0200
Subject: [PATCH] Avoid IEEE simplification as a side effect of defloating

---
 src/__tests__/fraction.spec.ts | 15 +++++++++++++++
 src/fraction.ts                | 15 ++++++---------
 2 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/src/__tests__/fraction.spec.ts b/src/__tests__/fraction.spec.ts
index b8c14ba..16c12e1 100644
--- a/src/__tests__/fraction.spec.ts
+++ b/src/__tests__/fraction.spec.ts
@@ -425,4 +425,19 @@ describe('Fraction', () => {
     expect(lensSum.lensSub(b).equals(a)).toBe(true);
     expect(lensSum.lensSub(a).equals(b)).toBe(true);
   });
+
+  it.fails('blows up on repeated division', () => {
+    let foo = new Fraction('3/2');
+    const bar = new Fraction('103/101');
+    for (let i = 0; i < 10; ++i) {
+      foo = foo.div(bar);
+    }
+  });
+
+  it.fails('blows up on repeated multiplication', () => {
+    let foo = new Fraction('103/101');
+    for (let i = 0; i < 4; ++i) {
+      foo = foo.mul(foo);
+    }
+  });
 });
diff --git a/src/fraction.ts b/src/fraction.ts
index 85e1234..4eb74bd 100644
--- a/src/fraction.ts
+++ b/src/fraction.ts
@@ -94,6 +94,12 @@ export class Fraction {
       this.s = Math.sign(numerator * denominator);
       this.n = Math.abs(numerator);
       this.d = Math.abs(denominator);
+      if (this.n > Number.MAX_SAFE_INTEGER) {
+        throw new Error('Numerator above safe limit');
+      }
+      if (this.d > Number.MAX_SAFE_INTEGER) {
+        throw new Error('Denominator above safe limit');
+      }
       if (this.d === 0) {
         throw new Error('Division by Zero');
       }
@@ -206,15 +212,6 @@ export class Fraction {
     if (isNaN(this.s) || isNaN(this.n) || isNaN(this.d)) {
       throw new Error('Cannot represent NaN as a fraction');
     }
-    /*
-    if (!isFinite(this.d)) {
-      if (!isFinite(this.n)) {
-        throw new Error('Both numerator and denominator cannot be infinite');
-      }
-      this.n = 0;
-      this.d = 1;
-    }
-    */
     if (this.n > Number.MAX_SAFE_INTEGER) {
       throw new Error('Numerator above safe limit');
     }