From a6481f1d3012a07e721ff080dc35c327f5c6cafe Mon Sep 17 00:00:00 2001
From: "Benjamin E. Coe" <bencoe@google.com>
Date: Fri, 6 Sep 2019 18:02:09 -0400
Subject: [PATCH] fix: don't load JSON that does not look like coverage (#146)

---
 lib/report.js | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/report.js b/lib/report.js
index 4e3af138..5746dc0f 100644
--- a/lib/report.js
+++ b/lib/report.js
@@ -110,11 +110,23 @@ class Report {
   _getMergedProcessCov () {
     const v8ProcessCovs = []
     for (const v8ProcessCov of this._loadReports()) {
-      v8ProcessCovs.push(this._normalizeProcessCov(v8ProcessCov))
+      if (this._isCoverageObject(v8ProcessCov)) {
+        v8ProcessCovs.push(this._normalizeProcessCov(v8ProcessCov))
+      }
     }
     return mergeProcessCovs(v8ProcessCovs)
   }
 
+  /**
+   * Make sure v8ProcessCov actually contains coverage information.
+   *
+   * @return {boolean} does it look like v8ProcessCov?
+   * @private
+   */
+  _isCoverageObject (maybeV8ProcessCov) {
+    return maybeV8ProcessCov && Array.isArray(maybeV8ProcessCov.result)
+  }
+
   /**
    * Returns the list of V8 process coverages generated by Node.
    *