[getopt] Add typo check for long options

3 files changed, 54 insertions, 0 deletions

diff --git a/library/cpp/getopt/small/last_getopt_opts.h b/library/cpp/getopt/small/last_getopt_opts.h
index 825b99c871..718dbfcb89 100644
--- a/library/cpp/getopt/small/last_getopt_opts.h
+++ b/library/cpp/getopt/small/last_getopt_opts.h
@@ -54,6 +54,7 @@ namespace NLastGetopt {
         bool AllowUnknownLongOptions_ = false;
 
         ui32 Wrap_ = 80;
+        bool CheckUserTypos_ = false;
 
     private:
         ui32 FreeArgsMin_; // minimal number of free args
@@ -341,6 +342,14 @@ namespace NLastGetopt {
         }
 
         /**
+         * Set check user typos or not
+         * @param check   bool flag for chosing
+         */
+        void SetCheckUserTypos(bool check = true) {
+            CheckUserTypos_ = check;
+        }
+
+        /**
          * Creates new [option description (TOpt)] for svn-revision printing,
          *   adds appropriate handler for it.
          * If "svnversion" option already exist, will add given short name to it.
diff --git a/library/cpp/getopt/small/last_getopt_parse_result.cpp b/library/cpp/getopt/small/last_getopt_parse_result.cpp
index f4b5607a90..60effba41b 100644
--- a/library/cpp/getopt/small/last_getopt_parse_result.cpp
+++ b/library/cpp/getopt/small/last_getopt_parse_result.cpp
@@ -119,6 +119,20 @@ namespace NLastGetopt {
         return Parser_->Argc_ - GetFreeArgsPos();
     }
 
+    void FindUserTypos(const TString& arg, const TOpts* options) {
+        if (arg.size() < 4 || !arg.StartsWith("-")) {
+            return;
+        }
+
+        for (auto opt: options->Opts_) {
+            for (auto name: opt->GetLongNames()) {
+                if ("-" + name == arg) {
+                    throw TUsageException() << "did you mean `-" << arg << "` (with two dashes)?";
+                }
+            }
+        }
+    }
+
     void TOptsParseResult::Init(const TOpts* options, int argc, const char** argv) {
         try {
             Parser_.Reset(new TOptsParser(options, argc, argv));
@@ -136,6 +150,12 @@ namespace NLastGetopt {
 
                 options->ArgBindings_[i](freeArgs[i]);
             }
+
+            if (options->CheckUserTypos_) {
+                for (auto arg: TVector<TString>(argv, std::next(argv, argc))) {
+                    FindUserTypos(arg, options);
+                }
+            }
         } catch (...) {
             HandleError();
         }
diff --git a/library/cpp/getopt/ut/last_getopt_ut.cpp b/library/cpp/getopt/ut/last_getopt_ut.cpp
index 6606000ca6..c2ee4f0c40 100644
--- a/library/cpp/getopt/ut/last_getopt_ut.cpp
+++ b/library/cpp/getopt/ut/last_getopt_ut.cpp
@@ -825,4 +825,29 @@ Y_UNIT_TEST_SUITE(TLastGetoptTests) {
         UNIT_ASSERT_VALUES_EQUAL(25, number);
         UNIT_ASSERT_VALUES_EQUAL(2, r.GetFreeArgCount());
     }
+
+    Y_UNIT_TEST(TestCheckUserTypos) {
+        {
+            TOptsNoDefault opts;
+            opts.SetCheckUserTypos();
+            opts.AddLongOption("from");
+            opts.AddLongOption("to");
+
+            UNIT_ASSERT_EXCEPTION(
+                    TOptsParseResultTestWrapper(&opts, V({"copy", "-from", "/home", "--to=/etc"})),
+                    TUsageException);
+            UNIT_ASSERT_NO_EXCEPTION(
+                    TOptsParseResultTestWrapper(&opts, V({"copy", "--from", "from", "--to=/etc"})));
+        }
+
+        {
+            TOptsNoDefault opts;
+            opts.SetCheckUserTypos();
+            opts.AddLongOption('f', "file", "");
+            opts.AddLongOption('r', "read", "");
+            opts.AddLongOption("fr");
+            UNIT_ASSERT_NO_EXCEPTION(
+                    TOptsParseResultTestWrapper(&opts, V({"copy", "-fr"})));
+        }
+    }
 }