Handle the fully-deductible case

[inverse-tax] / tax.test.js

diff --git a/tax.test.js b/tax.test.js
index 14c48c04481eddd4bb8c30809412d62ae1fdeda5..125cc2091cccd1587c27d9687e10271864f20066 100644 (file)
--- a/tax.test.js
+++ b/tax.test.js
@@ -57,5 +57,6 @@ test("invert", () => {
   assert.strictEqual(invert([                  ])(10), 10);
   assert.strictEqual(invert([[ 0, Infinity, .1]])( 9), 10);
   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);
 });