From 930f81a442169e9fbd76955252857625dc19c2e4 Mon Sep 17 00:00:00 2001
From: Kevin Goslar <kevin.goslar@gmail.com>
Date: Fri, 19 Jul 2019 10:29:20 -0500
Subject: [PATCH] Null checks

---
 src/index.ts                  | 12 ++++++------
 test/chars-test.ts            |  4 ++++
 test/json-test.ts             |  3 +++
 test/trimmed-lines-test.ts    |  4 ++++
 test/words-with-space-test.ts |  4 ++++
 5 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index f56d133..081465d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -10,10 +10,10 @@ export function chars(
   expected: string,
   message = "mismatching strings"
 ) {
-  if (!actual) {
+  if (actual == null) {
     throw new Error("AssertNoDiff: actual value not provided")
   }
-  if (!expected) {
+  if (expected == null) {
     throw new Error("AssertNoDiff: expected value not provided")
   }
   const differences = diff.diffChars(expected, actual)
@@ -53,10 +53,10 @@ export function trimmedLines(
   expected: string,
   message = "mismatching lines"
 ) {
-  if (!actual) {
+  if (actual == null) {
     throw new Error("AssertNoDiff: actual value not provided")
   }
-  if (!expected) {
+  if (expected == null) {
     throw new Error("AssertNoDiff: expected value not provided")
   }
   const differences = diff.diffTrimmedLines(expected, actual)
@@ -75,10 +75,10 @@ export function wordsWithSpace(
   expected: string,
   message = "mismatching words"
 ) {
-  if (!actual) {
+  if (actual == null) {
     throw new Error("AssertNoDiff: actual value not provided")
   }
-  if (!expected) {
+  if (expected == null) {
     throw new Error("AssertNoDiff: expected value not provided")
   }
   const differences = diff.diffWordsWithSpace(expected, actual)
diff --git a/test/chars-test.ts b/test/chars-test.ts
index 7fc2b65..a64498b 100644
--- a/test/chars-test.ts
+++ b/test/chars-test.ts
@@ -44,4 +44,8 @@ describe("assertNoDiff.chars", function() {
     }
     throw new Error("assertNoDiff.chars didn't throw")
   })
+
+  it("allows diffing against empty strings", function() {
+    assertNoDiff.chars("", "")
+  })
 })
diff --git a/test/json-test.ts b/test/json-test.ts
index f10208e..afba28d 100644
--- a/test/json-test.ts
+++ b/test/json-test.ts
@@ -44,4 +44,7 @@ describe("assertNoDiff.json", function() {
     }
     throw new Error("assertNoDiff.json didn't throw")
   })
+  it("allows diffing empty objects", function() {
+    assertNoDiff.json({}, {})
+  })
 })
diff --git a/test/trimmed-lines-test.ts b/test/trimmed-lines-test.ts
index e464734..ea5c10b 100644
--- a/test/trimmed-lines-test.ts
+++ b/test/trimmed-lines-test.ts
@@ -51,4 +51,8 @@ describe("assertNoDiff.trimmedLines", function() {
     }
     throw new Error("assertNoDiff.trimmedLines didn't throw")
   })
+
+  it("allows diffing against empty strings", function() {
+    assertNoDiff.trimmedLines("", "")
+  })
 })
diff --git a/test/words-with-space-test.ts b/test/words-with-space-test.ts
index 232c1a7..aa7466c 100644
--- a/test/words-with-space-test.ts
+++ b/test/words-with-space-test.ts
@@ -56,4 +56,8 @@ describe("assertNoDiff.wordsWithSpace", function() {
     }
     throw new Error("assertNoDiff.wordsWithSpace didn't throw")
   })
+
+  it("allows diffing against empty strings", function() {
+    assertNoDiff.wordsWithSpace("", "")
+  })
 })