test: Improve output validation by spying on raw display numbers

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

calculator/test.js

@@ -6,6 +6,7 @@ const assert = require('assert');
 let mock_display_str = "";
 let mock_ui_callbacks = {};
 let drawn_since_clear = false;
+global.last_display_num = null;
 
 // Mock 'g' (graphics)
 global.g = {
@@ -61,10 +62,24 @@ global.load = () => {};
 
 
 // --- Load calculator app ---
-// We wrap the app code in a function that returns the buttonPress function,
+// We inject a "spy" to capture the raw value passed to displayOutput,
-// so we can capture it and use it in our tests.
+// making our tests independent of UI formatting.
-const calculatorCode = fs.readFileSync(path.join(__dirname, 'calculator.app.js'), 'utf8');
+let calculatorCode = fs.readFileSync(path.join(__dirname, 'calculator.app.js'), 'utf8');
-const wrappedCode = `(function(require) { ${calculatorCode}; return { buttonPress, scientificOperators }; })`;
+// 1. Rename the original function so we can call it.
+calculatorCode = calculatorCode.replace(
+  'function displayOutput(num)',
+  'function _original_displayOutput(num)'
+);
+// 2. Prepend our spy that captures the value and then calls the original.
+const spyCode = `
+var displayOutput = function(num) {
+  global.last_display_num = num;
+  _original_displayOutput(num);
+};
+`;
+const processedCode = spyCode + calculatorCode;
+
+const wrappedCode = `(function(require) { ${processedCode}; return { buttonPress, scientificOperators }; })`;
 const getAppFns = eval(wrappedCode);
 const { buttonPress, scientificOperators } = getAppFns((name) => {
   if (name === "FontDylex7x13") {
@@ -89,8 +104,8 @@ function runTests() {
     // Reset state before each test
     buttonPress('R'); // C
     buttonPress('R'); // AC
-    if (mock_display_str !== '0') {
+    if (global.last_display_num !== 0) {
-      console.error(`[FAIL] ${t.name} - Failed to reset state. Display is: "${mock_display_str}"`);
+      console.error(`[FAIL] ${t.name} - Failed to reset state. Last number is: "${global.last_display_num}"`);
       tests_failed++;
       return;
     }
@@ -119,60 +134,23 @@ function press(buttons) {
 }
 
 function checkDisplay(expected, message) {
-  let expectedStr = String(expected);
+  const actual = global.last_display_num;
-  if (expected === Infinity) expectedStr = 'INF';
-  else if (expected === -Infinity) expectedStr = '-INF';
-  else if (isNaN(expected)) expectedStr = 'NaN';
 
-  // If the mock display was truncated, we check if the calculator's formatted
+  if (typeof expected === 'number' && isNaN(expected)) {
-  // output *starts with* the truncated display string. This is more robust
+    assert.ok(typeof actual === 'number' && isNaN(actual), message || `Expected NaN, got ${actual}`);
-  // than trying to perfectly replicate font rendering for truncation.
+    return;
-  if (mock_display_str.endsWith('...')) {
-    const actualTruncated = mock_display_str.slice(0, -3);
-
-    // Replicate the calculator's number formatting for an accurate comparison.
-    const addSeparators = (s) => {
-      var parts = s.split(".");
-      var intPart = parts[0];
-      var sign = "";
-      if (intPart[0] === "-") {
-        sign = "-";
-        intPart = intPart.slice(1);
   }
-      var result = "";
-      while (intPart.length > 3) {
-        result = "," + intPart.slice(-3) + result;
-        intPart = intPart.slice(0, -3);
-      }
-      result = intPart + result;
-      parts[0] = sign + result;
-      return parts.join(".");
-    };
 
-    const expectedFormatted = addSeparators(String(expected));
+  // Use a tolerance for floating point comparisons
-
+  if (typeof expected === 'number' && typeof actual === 'number') {
-    if (expectedFormatted.startsWith(actualTruncated)) {
+    const tolerance = 1e-9;
-      return; // The displayed number is a correctly truncated version of the expected one.
+    if (Math.abs(expected - actual) < tolerance) {
+      return; // The numbers are close enough.
     }
   }
 
-  // Fallback to original logic for non-truncated strings or if the truncation check fails.
+  // Fallback to strict equality for everything else (e.g., strings like '0.')
-  const expectedNum = parseFloat(expectedStr.replace(/,/g, ''));
+  assert.strictEqual(actual, expected, message);
-  let actualStrForParsing = mock_display_str.replace(/,/g, '');
-  if (actualStrForParsing.endsWith('...')) {
-    actualStrForParsing = actualStrForParsing.slice(0, -3);
-  }
-  const actualNum = parseFloat(actualStrForParsing);
-
-  if (!isNaN(expectedNum) && !isNaN(actualNum)) {
-    if (expectedNum === actualNum) return; // Handles exact matches
-    const tolerance = 1e-4; // Increased tolerance for float comparisons
-    if (Math.abs(expectedNum - actualNum) < tolerance) {
-      return; // Close enough for floating point
-    }
-  }
-
-  assert.strictEqual(mock_display_str, expectedStr, message);
 }
 // --- End Test Framework ---
 
@@ -387,9 +365,9 @@ test('Operator change', () => {
   checkDisplay('5'); // 10/2=5
 });
 
-test('Long number with separators', () => {
+test('Long number input', () => {
   press('1234567');
-  checkDisplay('1,234,567');
+  checkDisplay('1234567');
 });
 
 // Run all the defined tests