diff --git a/calculator/test.js b/calculator/test.js
index b6a58c8..41323f9 100644
--- a/calculator/test.js
+++ b/calculator/test.js
@@ -145,35 +145,165 @@ function checkDisplay(expected, message) {
 
 // --- Test Cases ---
 
-test('Addition', () => {
-  press('1+2=');
-  checkDisplay('3');
+const testNumbers = [
+  0, 1, -1, 5, -5, 0.5, -0.5, 123, -123, 1.23, -1.23,
+  1234567, -1234567, 99999999, -99999999,
+  1e-6, -1e-6, Math.PI, Math.E
+];
+
+// Helper to press a number, handling negatives
+function pressNumber(n) {
+  const s = String(n);
+  if (s.startsWith('-')) {
+    press(s.substring(1));
+    buttonPress('N');
+  } else {
+    press(s);
+  }
+}
+
+// --- Generated Tests: Binary Operations ---
+const binaryOps = {
+  '+': (a, b) => a + b,
+  '-': (a, b) => a - b,
+  '*': (a, b) => a * b,
+  '/': (a, b) => a / b,
+};
+
+for (const op in binaryOps) {
+  for (const a of testNumbers) {
+    for (const b of testNumbers) {
+      if (op === '/' && b === 0) {
+        test(`Binary Edge Case: ${a} / 0`, () => {
+          pressNumber(a);
+          buttonPress('/');
+          pressNumber(0);
+          buttonPress('=');
+          checkDisplay(a === 0 ? NaN : (a > 0 ? Infinity : -Infinity));
+        });
+        continue;
+      }
+
+      test(`Binary: ${a} ${op} ${b}`, () => {
+        pressNumber(a);
+        buttonPress(op);
+        pressNumber(b);
+        buttonPress('=');
+        const expected = binaryOps[op](a, b);
+        checkDisplay(expected);
+      });
+    }
+  }
+}
+
+// --- Generated Tests: Unary Operations ---
+const unaryOps = {
+  'r': { name: 'sqrt', fn: Math.sqrt },
+  's': { name: 'x^2', fn: (a) => a * a },
+  'i': { name: '1/x', fn: (a) => 1 / a },
+  '%': { name: '%', fn: (a) => a / 100 },
+};
+
+for (const op in unaryOps) {
+  for (const a of testNumbers) {
+    if (op === 'r' && a < 0) {
+      test(`Unary Edge Case: sqrt(${a})`, () => {
+        pressNumber(a);
+        buttonPress('r');
+        checkDisplay(NaN);
+      });
+      continue;
+    }
+
+    test(`Unary: ${unaryOps[op].name}(${a})`, () => {
+      pressNumber(a);
+      buttonPress(op);
+      const expected = unaryOps[op].fn(a);
+      checkDisplay(expected);
+    });
+  }
+}
+
+// --- 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 chainOps = ['+', '-', '*', '/'];
+
+for (const a of chainNumbers) {
+  for (const b of chainNumbers) {
+    for (const c of chainNumbers) {
+      for (const op1 of chainOps) {
+        for (const op2 of chainOps) {
+          test(`Chaining: ${a} ${op1} ${b} ${op2} ${c}`, () => {
+            pressNumber(a);
+            buttonPress(op1);
+            pressNumber(b);
+            buttonPress(op2); // This will execute the first operation
+            pressNumber(c);
+            buttonPress('='); // This will execute the second operation
+            // Calculator does sequential evaluation: (a op1 b) op2 c
+            const expected = binaryOps[op2](binaryOps[op1](a, b), c);
+            checkDisplay(expected);
+          });
+        }
+      }
+    }
+  }
+}
+
+// --- Generated Tests: Trigonometry ---
+const trigOps = {
+  'sin': { fn: Math.sin, name: 'sin' },
+  '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];
+
+// Test in DEG mode (default)
+for (const op in trigOps) {
+  for (const angle of trigAngles) {
+    test(`Trig (deg): ${trigOps[op].name}(${angle})`, () => {
+      pressNumber(angle);
+      buttonPress(op);
+      const expected = trigOps[op].fn(angle * Math.PI / 180);
+      checkDisplay(expected);
+    });
+  }
+}
+
+// Test in RAD mode
+test('Switch to RAD mode', () => {
+  buttonPress('angleMode');
+  assert.strictEqual(scientificOperators.angleMode.val, 'rad');
 });
 
-test('Subtraction', () => {
-  press('9-5=');
-  checkDisplay('4');
+for (const op in trigOps) {
+  for (const angle of trigAngles) {
+    // tan(pi/2) is Infinity, which the calculator can handle
+    if (op === 'tan' && (Math.abs(angle - Math.PI/2) < 1e-9 || Math.abs(angle - 3*Math.PI/2) < 1e-9)) {
+       test(`Trig Edge Case (rad): tan(${angle})`, () => {
+        pressNumber(angle);
+        buttonPress('tan');
+        checkDisplay(Infinity);
+      });
+      continue;
+    }
+    test(`Trig (rad): ${trigOps[op].name}(${angle})`, () => {
+      pressNumber(angle);
+      buttonPress(op);
+      const expected = trigOps[op].fn(angle);
+      checkDisplay(expected);
+    });
+  }
+}
+
+test('Switch back to DEG mode for subsequent tests', () => {
+  buttonPress('angleMode');
+  assert.strictEqual(scientificOperators.angleMode.val, 'deg');
 });
 
-test('Multiplication', () => {
-  press('3*4=');
-  checkDisplay('12');
-});
 
-test('Division', () => {
-  press('10/2=');
-  checkDisplay('5');
-});
-
-test('Chained operations (no precedence)', () => {
-  press('2+3*4='); // (2+3)*4 = 20
-  checkDisplay('20');
-});
-
-test('Decimal numbers', () => {
-  press('1.5+2.5=');
-  checkDisplay('4');
-});
+// --- Specific Functionality Tests ---
 
 test('Clear and All Clear', () => {
   press('123+');
@@ -191,54 +321,10 @@ test('Clear and All Clear', () => {
   checkDisplay('1');
 });
 
-
-test('Negative result', () => {
-  press('5-10=');
-  checkDisplay('-5');
-});
-
-test('Negative input', () => {
-  press('5*');
-  press('2');
-  press('N'); // make it -2
-  press('=');
-  checkDisplay('-10');
-});
-
-test('Division by zero', () => {
-  press('5/0=');
-  checkDisplay('INF');
-});
-
-test('Percentage', () => {
-  press('200*5%=');
-  checkDisplay('10');
-});
-
-test('Square root', () => {
-  press('16');
-  press('r');
-  checkDisplay('4');
-  press('='); // pressing equals after unary op
-  checkDisplay('4');
-});
-
-test('Square', () => {
-  press('5');
-  press('s');
-  checkDisplay('25');
-  press('=');
-  checkDisplay('25');
-});
-
-test('Inverse', () => {
-  press('4');
-  press('i');
-  checkDisplay('0.25');
-});
-
 test('Backspace', () => {
-  press('123B');
+  press('123.45B');
+  checkDisplay('123.4');
+  press('BB');
   checkDisplay('12');
   press('B');
   checkDisplay('1');
@@ -255,6 +341,11 @@ test('Repeated equals', () => {
   checkDisplay('8');
   press('=');
   checkDisplay('11');
+  press('R'); press('R');
+  press('10-2=');
+  checkDisplay('8');
+  press('=');
+  checkDisplay('6');
 });
 
 test('Operator change', () => {
@@ -267,42 +358,5 @@ test('Long number with separators', () => {
   checkDisplay('1,234,567');
 });
 
-test('Sine (deg)', () => {
-  press('30');
-  buttonPress('sin');
-  checkDisplay('0.5');
-  press('R'); press('R');
-  press('90');
-  buttonPress('sin');
-  checkDisplay('1');
-  press('R'); press('R');
-  press('180');
-  buttonPress('sin');
-  checkDisplay('0');
-});
-
-test('Cosine (deg)', () => {
-  press('60');
-  buttonPress('cos');
-  checkDisplay('0.5');
-  press('R'); press('R');
-  press('0');
-  buttonPress('cos');
-  checkDisplay('1');
-  press('R'); press('R');
-  press('90');
-  buttonPress('cos');
-  checkDisplay('0');
-});
-
-test('Angle mode switch to radians and back', () => {
-    buttonPress('angleMode'); // now rad
-    // The buttonPress function doesn't return the state, but we can check the object it modifies
-    assert.strictEqual(scientificOperators.angleMode.val, 'rad');
-    buttonPress('angleMode'); // back to deg
-    assert.strictEqual(scientificOperators.angleMode.val, 'deg');
-});
-
-
 // Run all the defined tests
 runTests();