Show error on shallow repositories

If a repository is shallow, we do not have access to the whole history,
which will cause our commit lookups to fail.

If a shallow repository is detected, an appropriate message is printed
out and the program exits.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/index.js b/src/index.js
index 9018fb9..dd1ad8f 100755
--- a/src/index.js
+++ b/src/index.js
@@ -5,6 +5,7 @@ var git = require('nodegit');
 var program = require('commander');
 var _ = require('lodash');
 var moment = require('moment');
+var fs = require('fs');
 
 var DATE_FORMAT = 'YYYY-MM-DD';
 
@@ -21,6 +22,8 @@ var config = {
 };
 
 function main() {
+    exitIfShallow();
+
     parseArgs();
     config = mergeDefaultsWithArgs(config);
     config.since = parseSinceDate(config.since);
@@ -61,6 +64,14 @@ function main() {
     });
 }
 
+function exitIfShallow() {
+    if (fs.existsSync(".git/shallow")) {
+        console.log("Cannot analyze shallow copies!");
+        console.log("Please run git fetch --unshallow before continuing!");
+        process.exit(1);
+    }
+}
+
 function parseArgs() {
     function int(val) {
         return parseInt(val, 10);