test: Add extensive edge case tests and expand number generation

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

calculator/test.js

@@ -161,12 +161,42 @@ function checkDisplay(expected, message) {
 
 // --- Test Cases ---
 
-const testNumbers = [
-  0, 1, -1, 5, -5, 0.5, -0.5, 123, -123, 1.23, -1.23,
+const basicNumbers = [
+  0, 1, -1, 2, -2, 5, -5, 10, -10, 0.1, -0.1, 0.2, -0.2, 0.5, -0.5,
+  123, -123, 1.23, -1.23,
   1234567, -1234567, 99999999, -99999999,
-  1e-6, -1e-6, Math.PI, Math.E
 ];
 
+const edgeCaseNumbers = [
+  -0,
+  Number.MAX_SAFE_INTEGER,
+  Number.MIN_SAFE_INTEGER,
+  Math.PI, Math.E,
+  1e-6, -1e-6, 1e-8, -1e-8,
+  1e6, -1e6, 1e8, -1e8,
+  0.1+0.2, // floating point fun
+  1/3, 2/3, 0.9999999, 1.0000001
+];
+
+// Generate some more numbers to reach the target count
+const generatedNumbers = [];
+for (let i = 1; i <= 20; i++) {
+    // integers
+    generatedNumbers.push(i * 123);
+    generatedNumbers.push(i * -123);
+    // floats
+    generatedNumbers.push(i / 10);
+    generatedNumbers.push(i / -10);
+    // small floats
+    generatedNumbers.push(i / 1000);
+    generatedNumbers.push(i / -1000);
+}
+
+const testNumbers = [...new Set([...basicNumbers, ...edgeCaseNumbers, ...generatedNumbers])];
+// We need to filter out Infinity/-Infinity for pressNumber helper as they can't be typed.
+// They can only appear as results, which we test for separately.
+const finiteTestNumbers = testNumbers.filter(n => isFinite(n));
+
 // Helper to press a number, handling negatives
 function pressNumber(n) {
   const s = String(n);
@@ -187,8 +217,8 @@ const binaryOps = {
 };
 
 for (const op in binaryOps) {
-  for (const a of testNumbers) {
-    for (const b of testNumbers) {
+  for (const a of finiteTestNumbers) {
+    for (const b of finiteTestNumbers) {
       if (op === '/' && b === 0) {
         test(`Binary Edge Case: ${a} / 0`, () => {
           pressNumber(a);
@@ -212,6 +242,85 @@ for (const op in binaryOps) {
   }
 }
 
+// --- Generated Tests: Operations with non-finite results ---
+const smallFiniteTestNumbers = [1, -1, 5, -5, 0, 100, -100]; // for speed
+
+// Test operations that result in Infinity, -Infinity, or NaN, and then continue with another operation
+for (const a of smallFiniteTestNumbers) {
+    // a / 0 -> Infinity/-Infinity/NaN
+    test(`Non-finite chaining: (${a} / 0) + 5`, () => {
+        pressNumber(a);
+        press('/0=');
+        const intermediate = a/0;
+        checkDisplay(intermediate);
+        press('+5=');
+        checkDisplay(intermediate + 5);
+    });
+
+    test(`Non-finite chaining: (${a} / 0) * 5`, () => {
+        pressNumber(a);
+        press('/0=');
+        const intermediate = a/0;
+        checkDisplay(intermediate);
+        press('*5=');
+        checkDisplay(intermediate * 5);
+    });
+
+    test(`Non-finite chaining: (${a} / 0) * 0`, () => {
+        pressNumber(a);
+        press('/0=');
+        const intermediate = a/0;
+        checkDisplay(intermediate);
+        press('*0=');
+        checkDisplay(intermediate * 0); // Should be NaN
+    });
+
+    test(`Non-finite chaining: (${a} / 0) / 5`, () => {
+        pressNumber(a);
+        press('/0=');
+        const intermediate = a/0;
+        checkDisplay(intermediate);
+        press('/5=');
+        checkDisplay(intermediate / 5);
+    });
+
+    test(`Non-finite chaining: (${a} / 0) / 0`, () => {
+        pressNumber(a);
+        press('/0=');
+        const intermediate = a/0;
+        checkDisplay(intermediate);
+        press('/0=');
+        checkDisplay(intermediate / 0);
+    });
+}
+// 0/0 = NaN. Test operations on NaN
+test(`Non-finite chaining: (0 / 0) + 5`, () => {
+    press('0/0=');
+    checkDisplay(NaN);
+    press('+5=');
+    checkDisplay(NaN + 5); // anything + NaN is NaN
+});
+test(`Non-finite chaining: (0 / 0) * 5`, () => {
+    press('0/0=');
+    checkDisplay(NaN);
+    press('*5=');
+    checkDisplay(NaN * 5);
+});
+test(`Non-finite chaining: (0 / 0) / 5`, () => {
+    press('0/0=');
+    checkDisplay(NaN);
+    press('/5=');
+    checkDisplay(NaN / 5);
+});
+test(`Non-finite chaining: sqrt(negative) then op`, () => {
+    press('9N'); // -9
+    press('r'); // sqrt
+    checkDisplay(NaN);
+    press('+1=');
+    checkDisplay(NaN);
+});
+
+
 // --- Generated Tests: Unary Operations ---
 const unaryOps = {
   'r': { name: 'sqrt', fn: Math.sqrt },
@@ -221,7 +330,7 @@ const unaryOps = {
 };
 
 for (const op in unaryOps) {
-  for (const a of testNumbers) {
+  for (const a of finiteTestNumbers) {
     if (op === 'r' && a < 0) {
       test(`Unary Edge Case: sqrt(${a})`, () => {
         pressNumber(a);
@@ -242,7 +351,7 @@ for (const op in unaryOps) {
 
 // --- Generated Tests: Chaining Operations ---
 // To keep runtime sane, we'll pick a smaller subset for chaining
-const chainNumbers = [0, 1, -5, 0.5, 10, 123];
+const chainNumbers = [0, 1, -1, 5, -5, 0.5, -0.5, 10, -10, 123, -123, 1.23];
 const chainOps = ['+', '-', '*', '/'];
 
 for (const a of chainNumbers) {
@@ -273,7 +382,7 @@ const trigOps = {
   'cos': { fn: Math.cos, name: 'cos' },
   'tan': { fn: Math.tan, name: 'tan' },
 };
-const trigAngles = [0, 30, 45, 60, 90, 180, 270, 360, Math.PI/6, Math.PI/4, Math.PI/2, Math.PI, 3*Math.PI/2, 2*Math.PI];
+const trigAngles = [0, 15, 30, 45, 60, 75, 90, 180, 270, 360, -30, -45, -90, -180, 450, 720, Math.PI/6, Math.PI/4, Math.PI/3, Math.PI/2, Math.PI, 3*Math.PI/2, 2*Math.PI, -Math.PI/2, -Math.PI];
 
 // Test in DEG mode (default)
 for (const op in trigOps) {
@@ -369,5 +478,24 @@ test('Long number input', () => {
   checkDisplay('1234567');
 });
 
+test('Input starting with decimal point', () => {
+  press('.5');
+  checkDisplay('0.5');
+  press('*2=');
+  checkDisplay('1');
+});
+
+test('Negative zero handling', () => {
+  press('0N'); // get -0
+  checkDisplay(-0);
+  press('*5');
+  checkDisplay(-0);
+  press('=');
+  checkDisplay(-0);
+  buttonPress('R'); buttonPress('R');
+  press('5*-0=');
+  checkDisplay(-0);
+});
+
 // Run all the defined tests
 runTests();