Fractions

lib/__test__/rule-list.test.js

@@ -172,21 +172,86 @@ describe('rules', () => {
         ['x^((x + 1) / -1)', 'x^(-(x + 1) / 1)'],
     ])
 
-    suite('add numerators', rules.COMBINE_NUMERATORS, [
+    suite('rewrite fractional polynomial', rules.REWRITE_FRACTIONAL_POLYNOMIAL, [
+        ['2x/3', '2 / 3 x'],
+        ['2x^2/3', '2 / 3 x^2'],
+        ['2(x+1)^2/3', '2 / 3 (x + 1)^2'],
+        ['2xyz/3', '2 / 3 xyz'],
+    ])
+
+    suite('combine numerators', rules.COMBINE_NUMERATORS, [
         ['1/3 + 2/3', '(1 + 2) / 3'],
         ['1/x + 2/x + 3/x', '(1 + 2 + 3) / x'],
         ['2/3 - 1/3', '(2 - 1) / 3'],
         ['(1/3 + 2/3) / x', '(1 + 2) / 3 / x'],
     ])
 
-    suite('common denominators', rules.COMMON_DENOMINATOR, [
+    suite('convert to fraction', rules.CONVERT_TO_FRACTION, [
+        ['2/3 + x', '2 / 3 + x / 1'],
+        ['2/3 - x', '2 / 3 - x / 1'],
+        ['2/3 - x - 2', '2 / 3 - x / 1 - 2 / 1'],
+        ['2/(3 + x) + 2 + (x + 1)^2', '2 / (3 + x) + 2 / 1 + (x + 1)^2 / 1'],
+        ['2.2 + 3/4', '11 / 5 + 3 / 4'],
+        ['1.33 + 2.12 + 2/3', '133 / 100 + 53 / 25 + 2 / 3'],
+        ['1.44 - 2 - 3/4', '36 / 25 - 2 / 1 - 3 / 4'],
+        ['-2 + 3.33 + 2/3', '-2 / 1 + 333 / 100 + 2 / 3']
+    ])
+
+    suite('cancel like terms', rules.CANCEL_LIKE_TERMS, [
+        // when all factors cancel
+        ['((x+1)(x+2)) / ((x+1)(x+2))', '1'],
+        ['(x y z) / (x y z)', '1'],
+        // one factor in numerator, none in denominator
+        ['(12(x+1)) / (x+1)', '12'],
+        ['(x y z) / (y z)', 'x'],
+        // TODO: handle nthRoots
+        //['nthRoot(x^2,2) nthRoot(x^3,3) / nthRoot(x^2,2)']
+        // multiple factors in numerator, none in denominator
+        ['(12(x+1)^2) / (x+1)', '12 (x + 1)^1'],
+        ['(x y z w) / (z w)', 'x y'],
+        // one factor in denominator, none in numerator
+        ['(x+1)^2 / (12(x+1)^2)', '1 / 12'],
+        ['(x y z) / (x y z w)', '1 / w'],
+        // multiple factors in denominator, none in numerator
+        ['(x+1)^2 / (12 (x+1)^3)', '1 / (12 (x + 1)^1)'],
+        ['(x y z) / (x y z a b c)', '1 / (a b c)'],
+        // one factor in numerator and denominator
+        ['((x+1)^2 (x+2)^3) / ((x+1)^2 (x+3)^3)', '(x + 2)^3 / (x + 3)^3'],
+        ['(x y z) / (y z w)', 'x / w'],
+        // one factor in denominator, multiple in numerator
+        ['(12(x+1)^2 (2x+1)^2) / (x+1)^3 ', '(12 (2 x + 1)^2) / (x + 1)^1'],
+        // one factor in numerator, multiple in denominator
+        ['(x+1)^3 / (12(x+1)^2 (x+2)^3)', '(x + 1)^1 / (12 (x + 2)^3)'],
+        ['(x y z) / (y z a b)', 'x / (a b)'],
+        // multiple factors in both numerator and denominator
+        ['(12(x+1)^2 (x+2)^2) / ((x+2)^3 (x+4)^2)', '(12 (x + 1)^2) / ((x + 2)^1 (x + 4)^2)'],
+        ['(a b c d) / (d e f g)', '(a b c) / (e f g)'],
+        // testing simplify fractions
+        ['(12(x+1)^2) / (8(x+2))', '(3 (x + 1)^2) / (2 (x + 2))'],
+    ])
+
+    suite('common denominators', rules.COMMON_DENOMINATOR, [ 
         ['2/6 + 1/4', '(2 * 2) / (6 * 2) + (1 * 3) / (4 * 3)'],
+        ['2/(3 + x) + 3/(2 + x)', '(2 (2 + x)) / ((3 + x) (2 + x)) + (3 (3 + x)) / ((3 + x) (2 + x))'],
+        ['2/5 + 1/(3x + 7)', '(2 (3 x + 7)) / (5 (3 x + 7)) + (1 * 5) / (5 (3 x + 7))'],
         ['2/6 - 1/4', '(2 * 2) / (6 * 2) - (1 * 3) / (4 * 3)'],
         ['2/6 + 1/4 - 2/5', '(2 * 10) / (6 * 10) + (1 * 15) / (4 * 15) - (2 * 12) / (5 * 12)'],
-        ['2/6 + 1/4 - 3/4', '(2 * 2) / (6 * 2) + (1 * 3) / (4 * 3) - (3 * 3) / (4 * 3)'],
-        // TODO: return the original expression if the denominators are already
-        // the same?
-        ['2/4 - 1/4', '(2 * 1) / (4 * 1) - (1 * 1) / (4 * 1)'],
+        ['2/6 + 1/4 - 3/4', '(2 * 2) / (6 * 2) + (1 * 3) / (4 * 3) - (3 * 3) / (4 * 3)'],  
+        ['(3 + x)/2 + 2/(3 + x) + 2/3', '((3 + x) 3 (3 + x)) / (6 (3 + x)) + (2 * 6) / (6 (3 + x)) + (2 2 (3 + x)) / (6 (3 + x))'],
+        // Some terms have same denom 
+        ['2/3 + 2/3 + 1/4 + 1/4', '(2 * 4) / (3 * 4) + (2 * 4) / (3 * 4) + (1 * 3) / (4 * 3) + (1 * 3) / (4 * 3)'],
+        // Number surrounded by fraction
+        ['3 + 2/3', '(3 * 3) / 3 + 2 / 3'],
+        ['x + 2 + 3/4', '(x * 4) / 4 + (2 * 4) / 4 + 3 / 4'],
+        ['(x + 1)^2 + 2/3', '((x + 1)^2 * 3) / 3 + 2 / 3'],
+        ['2(x + 1)^2 + 2/3', '(2 (x + 1)^2 * 3) / 3 + 2 / 3'],
+        ['2/3 - x - 2', '2 / 3 - (x * 3) / 3 - (2 * 3) / 3'],
+        ['2/3 - x/3 - 2/4', '(2 * 4) / (3 * 4) - (x * 4) / (3 * 4) - (2 * 3) / (4 * 3)'],
+        ['-2 + 3 - 2/4', '-(2 * 4) / 4 + (3 * 4) / 4 - 2 / 4'],
+        ['2 / x + 3 / (x + 1)^2', '(2 (x + 1)^2) / (x (x + 1)^2) + (3 x) / (x (x + 1)^2)'],
+        ['2 / (4 * x) + 2 / y', '(2 y) / (4 x y) + (2 (4 x)) / (4 x y)'],
+        // TODO: case doesn't work, but is fine because polynomials should be simplified
+        //['2 / (x * x) + 3 / (x * y) + 4 / (y * y)', ''],
     ])
 
     suite('multiply fractions', rules.MULTIPLY_FRACTIONS, [
@@ -491,3 +556,4 @@ describe('canApplyRule', () => {
         })
     })
 })
+