fix #3163: toTex wrongly returning Infinity for large BigNumbers

josdejong · Feb 23, 2024 · 50b15a7 · 50b15a7
1 parent 4c42a14
commit 50b15a7
Show file tree

Hide file tree

Showing 3 changed files with 27 additions and 14 deletions.
diff --git a/HISTORY.md b/HISTORY.md
@@ -1,6 +1,11 @@
 # History
 
 
+# unpublished changes since 12.4.0
+
+- Fix #3163: `toTex` wrongly returning `Infinity` for large BigNumbers. 
+
+
 # 2024-02-22, 12.4.0
 
 - Feat: implement support for trailing commas in matrices (#3154, #2968).

diff --git a/src/expression/node/ConstantNode.js b/src/expression/node/ConstantNode.js
@@ -140,27 +140,30 @@ export const createConstantNode = /* #__PURE__ */ factory(name, dependencies, ({
      */
     _toTex (options) {
       const value = this._toString(options)
+      const type = typeOf(this.value)
 
-      switch (typeOf(this.value)) {
+      switch (type) {
         case 'string':
           return '\\mathtt{' + escapeLatex(value) + '}'
 
         case 'number':
-        case 'BigNumber':
-          {
-            if (!isFinite(this.value)) {
-              return (this.value.valueOf() < 0)
-                ? '-\\infty'
-                : '\\infty'
-            }
-
-            const index = value.toLowerCase().indexOf('e')
-            if (index !== -1) {
-              return value.substring(0, index) + '\\cdot10^{' +
-                value.substring(index + 1) + '}'
-            }
+        case 'BigNumber': {
+          const finite = type === 'BigNumber' ? this.value.isFinite() : isFinite(this.value)
+          if (!finite) {
+            return (this.value.valueOf() < 0)
+              ? '-\\infty'
+              : '\\infty'
+          }
+
+          const index = value.toLowerCase().indexOf('e')
+          if (index !== -1) {
+            return value.substring(0, index) + '\\cdot10^{' +
+              value.substring(index + 1) + '}'
           }
+
           return value
+        }
+
         case 'Fraction':
           return this.value.toLatex()
 

diff --git a/test/unit-tests/expression/node/ConstantNode.test.js b/test/unit-tests/expression/node/ConstantNode.test.js
@@ -189,6 +189,11 @@ describe('ConstantNode', function () {
     assert.strictEqual(new ConstantNode(3).toTex(), '3')
     assert.deepStrictEqual(new ConstantNode(3).toTex(), '3')
     assert.deepStrictEqual(new ConstantNode(math.bignumber('3')).toTex(), '3')
+    assert.deepStrictEqual(new ConstantNode(math.bignumber('1.3e7')).toTex(), '1.3\\cdot10^{+7}')
+    assert.deepStrictEqual(new ConstantNode(math.bignumber('1e500')).toTex(), '1\\cdot10^{+500}')
+    assert.deepStrictEqual(new ConstantNode(math.bignumber('1e-500')).toTex(), '1\\cdot10^{-500}')
+    assert.deepStrictEqual(new ConstantNode(math.bignumber('12345678901234567890')).toTex(),
+      '1.234567890123456789\\cdot10^{+19}')
     assert.strictEqual(new ConstantNode('hi').toTex(), '\\mathtt{"hi"}')
     assert.strictEqual(new ConstantNode(true).toTex(), 'true')
     assert.strictEqual(new ConstantNode(false).toTex(), 'false')