Always omit at least two lines in string diffs

unexpectedjs · May 1, 2019 · eba60ba · eba60ba
1 parent bf6dd37
commit eba60ba
Show file tree

Hide file tree

Showing 2 changed files with 37 additions and 6 deletions.
diff --git a/lib/styles.js b/lib/styles.js
@@ -203,9 +203,7 @@ module.exports = expect => {
   });
 
   expect.addStyle('diffLinesOmitted', function(lineCount) {
-    this.jsComment(
-      `... ${lineCount} line${lineCount === 1 ? '' : 's'} omitted ...`
-    );
+    this.jsComment(`... ${lineCount} lines omitted ...`);
   });
 
   expect.addStyle('removedHighlight', function(content) {
@@ -471,7 +469,7 @@ module.exports = expect => {
           );
         } else {
           const horizon = 3;
-          if (index === diffLines.length - 1 && part.count > horizon) {
+          if (index === diffLines.length - 1 && part.count > horizon + 1) {
             this.stringDiffFragment(
               ' ',
               value
@@ -482,7 +480,7 @@ module.exports = expect => {
             )
               .nl()
               .diffLinesOmitted(part.count - horizon);
-          } else if (index === 0 && part.count > horizon) {
+          } else if (index === 0 && part.count > horizon + 1) {
             this.diffLinesOmitted(part.count - horizon)
               .nl()
               .stringDiffFragment(
@@ -493,7 +491,7 @@ module.exports = expect => {
                   .join('\n'),
                 'text'
               );
-          } else if (part.count > 2 * horizon) {
+          } else if (part.count > 2 * horizon + 1) {
             this.stringDiffFragment(
               ' ',
               value

diff --git a/test/assertions/to-be.spec.js b/test/assertions/to-be.spec.js
@@ -146,6 +146,39 @@ describe('to be assertion', () => {
       );
     });
 
+    // These would be annoying to look at
+    it('does not produce ... 1 lines omitted ... lines', () => {
+      expect(
+        () =>
+          expect(
+            'a\nb\nc\nd\ne\nf\ng\nh\ni\nj\nk\nl\nm\nn\no\np\nq\n',
+            'to equal',
+            'a\nb\nc\nd\nf\ng\nh\ni\nj\nk\nl\nn\no\np\nq\n'
+          ),
+        'to throw',
+        "expected 'a\\nb\\nc\\nd\\ne\\nf\\ng\\nh\\ni\\nj\\nk\\nl\\nm\\nn\\no\\np\\nq\\n'\n" +
+          "to equal 'a\\nb\\nc\\nd\\nf\\ng\\nh\\ni\\nj\\nk\\nl\\nn\\no\\np\\nq\\n'\n" +
+          '\n' +
+          ' a\n' +
+          ' b\n' +
+          ' c\n' +
+          ' d\n' +
+          '-e\n' +
+          ' f\n' +
+          ' g\n' +
+          ' h\n' +
+          ' i\n' +
+          ' j\n' +
+          ' k\n' +
+          ' l\n' +
+          '-m\n' +
+          ' n\n' +
+          ' o\n' +
+          ' p\n' +
+          ' q\n'
+      );
+    });
+
     it('truncates lines in large in the start and end', () => {
       const paragraphs = `\
         Bacon ipsum dolor amet tri-tip kielbasa kevin spare ribs. Sirloin chuck jerky