Add --max-warnings [int] option

solhint.js

@@ -14,7 +14,8 @@ function init() {
     program
         .usage('[options] <file> [...other_files]')
         .option('-f, --formatter [name]', 'report formatter name (stylish, table, tap, unix)')
-        .option('-q, --quiet', 'report errors only - default: false')
+        .option('-w, --max-warnings [maxWarningsNumber]', 'number of warnings to trigger nonzero exit code')
+        .option('-q, --quiet', 'report errors only')
         .description('Linter for Solidity programming language')
         .action(execMainAction);
 
@@ -39,13 +40,22 @@ function init() {
 function execMainAction() {
     const reportLists = program.args.filter(_.isString).map(processPath);
     const reports =_.flatten(reportLists);
+    const warningsNumberExceeded = program.maxWarnings >= 0 && reports[0].warningCount >= program.maxWarnings;
 
     if (program.quiet) {
         // filter the list of reports, to set errors only.
         reports[0].reports  = reports[0].reports.filter(i => i.severity === 2);
     }
 
-    printReports(reports, program.formatter);
+    if (printReports(reports, program.formatter)) {
+        if (program.maxWarnings && !reports[0].errorCount && warningsNumberExceeded) {
+            console.log(
+                'Solhint found more warnings than the maximum specified (maximum: %s)',
+                program.maxWarnings);
+            process.exit(1);
+        }
+    }
+
     exitWithCode(reports);
 }