X-Git-Url: http://git.scottworley.com/inverse-tax/blobdiff_plain/49188cbe174f6f0559037bb2f6e51300dac90a85..30e3d4e3fa65d78bad3fc3a14e077db5baed35f6:/tax.test.js?ds=inline diff --git a/tax.test.js b/tax.test.js index 125cc20..21b98b6 100644 --- a/tax.test.js +++ b/tax.test.js @@ -59,4 +59,16 @@ test("invert", () => { assert.strictEqual(invert([[10, Infinity, .1]])(19), 20); assert.strictEqual(invert([[10, Infinity, .1]])( 9), 9); assert.strictEqual(invert([[0, 100, .1], [100, Infinity, .2]])(170), 200); + assert.strictEqual(invert([[0, 100, .1], [100, Infinity, .2]])(112), 127.5); + assert.strictEqual(invert([[6, 90, 0.75], [90, Infinity, 0.12]])(27), 90); + + for (var i = 0; i < 1000; i++) { + const t = make_random_tax_table(); + const inverted_t = invert(t); + for (var j = 0; j < 20; j++) { + const net = rand(250); + const gross = inverted_t(net); + assert.ok(near(net, gross - tax(t, gross))); + } + } });