fix: nested summarizer error with no files (#230)

* Fix issue where error was thrown when there were no files and using nested summarizer * Add unit test to catch issue * Fix linting error * Rename unit test
istanbuljs · Dec 28, 2018 · 07724bf · 07724bf
1 parent b2c1e8c
commit 07724bf
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diff --git a/packages/istanbul-lib-report/lib/summarizer.js b/packages/istanbul-lib-report/lib/summarizer.js
@@ -232,7 +232,7 @@ function createNestedSummary(coverageMap) {
         root;
 
     if (topNodes.length === 0) {
-        return treeFor(new ReportNode([]));
+        return treeFor(new ReportNode(new Path([])));
     }
 
     if (topNodes.length === 1) {

diff --git a/packages/istanbul-lib-report/test/summarizer.test.js b/packages/istanbul-lib-report/test/summarizer.test.js
@@ -321,6 +321,14 @@ describe('summarizer', function() {
             assert.deepEqual(nodes, ['g:']);
         });
 
+        it('handles getting root node name without crashing when empty coverage map', function() {
+            var map = coverage.createCoverageMap({}),
+                tree = fn(map),
+                root = tree.getRoot(),
+                rootNodeName = root.getRelativeName();
+            assert.equal(rootNodeName, '');
+        });
+
         it('supports a list of files at top-level', function() {
             var map = singleDirMap(),
                 tree = fn(map),