From 650d2dba1fafa469a4a7a790f48dad5b33705feb Mon Sep 17 00:00:00 2001
From: skywing <skywing@users.noreply.github.com>
Date: Thu, 20 Jun 2019 07:11:16 -0400
Subject: [PATCH] Warn/error about unsupported flags #468

Warn/error about unsupported flags #468
---
 packages/truffle-core/lib/command.js   | 29 ++++++++++++++++++++++++++
 packages/truffle-core/test/commands.js | 21 +++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/packages/truffle-core/lib/command.js b/packages/truffle-core/lib/command.js
index 9fde2b76890..a62dafd7a6e 100644
--- a/packages/truffle-core/lib/command.js
+++ b/packages/truffle-core/lib/command.js
@@ -100,6 +100,35 @@ class Command {
       }
     });
 
+    //Check unsupported command line flag according to the option list in help
+    try {
+      const inputOptions = [];
+      inputStrings.map(i => {
+        if (i.startsWith("--")) {
+          inputOptions.push(i);
+        }
+      });
+
+      const validOptions = [];
+      result.command.help.options.map(item => {
+        let opt = item.option.split(" ")[0];
+        if (opt.startsWith("--")) validOptions.push(opt);
+      });
+
+      let notValidOptions = inputOptions.filter(
+        opt => !validOptions.includes(opt)
+      );
+
+      if (notValidOptions.length > 0)
+        return callback(
+          new TaskError(
+            "Unsupported (Undocumented) command line option: " + notValidOptions
+          )
+        );
+    } catch (err) {
+      callback(err);
+    }
+
     const newOptions = Object.assign({}, clone, argv);
 
     try {
diff --git a/packages/truffle-core/test/commands.js b/packages/truffle-core/test/commands.js
index bc649bddc20..50ae5086b4b 100644
--- a/packages/truffle-core/test/commands.js
+++ b/packages/truffle-core/test/commands.js
@@ -37,4 +37,25 @@ describe("Commander", function() {
     var actualCommand = commander.getCommand("console").command;
     assert.equal(actualCommand, commands.console);
   });
+
+  it("will stop and display error for unsupported flags in commands", function() {
+    var actualCommand = commander.getCommand("mig").command;
+    assert.equal(actualCommand, commands.migrate);
+    commander.run(
+      [
+        "migrate",
+        "--network",
+        "localhost",
+        "--unsupportedflag",
+        "invalidoption"
+      ],
+      { noAliases: true },
+      function(err) {
+        assert.equal(
+          err.message.split(":")[0],
+          "Unsupported (Undocumented) command line option"
+        );
+      }
+    );
+  });
 });