add const version of validator modifiers

include/CLI/Validators.hpp

@@ -43,7 +43,7 @@ class Validator {
     std::function<std::string(std::string &)> func_{[](std::string &) { return std::string{}; }};
     /// The name for search purposes of the Validator
     std::string name_;
-    /// A validate will only apply to an indexed value (-1 is all elements)
+    /// A Validator will only apply to an indexed value (-1 is all elements)
     int application_index_ = -1;
     /// Enable for Validator to allow it to be disabled if need be
     bool active_{true};
@@ -54,7 +54,7 @@ class Validator {
     Validator() = default;
     /// Construct a Validator with just the description string
     explicit Validator(std::string validator_desc) : desc_function_([validator_desc]() { return validator_desc; }) {}
-    // Construct Validator from basic information
+    /// Construct Validator from basic information
     Validator(std::function<std::string(std::string &)> op, std::string validator_desc, std::string validator_name = "")
         : desc_function_([validator_desc]() { return validator_desc; }), func_(std::move(op)),
           name_(std::move(validator_name)) {}
@@ -90,6 +90,12 @@ class Validator {
         desc_function_ = [validator_desc]() { return validator_desc; };
         return *this;
     }
+    /// Specify the type string
+    Validator description(std::string validator_desc) const {
+        Validator newval(*this);
+        newval.desc_function_ = [validator_desc]() { return validator_desc; };
+        return newval;
+    }
     /// Generate type description information for the Validator
     std::string get_description() const {
         if(active_) {
@@ -102,6 +108,12 @@ class Validator {
         name_ = std::move(validator_name);
         return *this;
     }
+    /// Specify the type string
+    Validator name(std::string validator_name) const {
+        Validator newval(*this);
+        newval.name_ = std::move(validator_name);
+        return newval;
+    }
     /// Get the name of the Validator
     const std::string &get_name() const { return name_; }
     /// Specify whether the Validator is active or not
@@ -109,6 +121,12 @@ class Validator {
         active_ = active_val;
         return *this;
     }
+    /// Specify whether the Validator is active or not
+    Validator active(bool active_val = true) const {
+        Validator newval(*this);
+        newval.active_ = active_val;
+        return newval;
+    }
 
     /// Specify whether the Validator can be modifying or not
     Validator &non_modifying(bool no_modify = true) {
@@ -120,6 +138,12 @@ class Validator {
         application_index_ = app_index;
         return *this;
     };
+    /// Specify the application index of a validator
+    Validator application_index(int app_index) const {
+        Validator newval(*this);
+        newval.application_index_ = app_index;
+        return newval;
+    };
     /// Get the current value of the application index
     int get_application_index() const { return application_index_; }
     /// Get a boolean if the validator is active

tests/AppTest.cpp

@@ -1077,8 +1077,9 @@ TEST_F(TApp, PositionalValidation) {
     std::string options;
     std::string foo;
 
-    app.add_option("bar", options)->check(CLI::Number);
-    app.add_option("foo", foo);
+    app.add_option("bar", options)->check(CLI::Number.name("valbar"));
+    // disable the check on foo
+    app.add_option("foo", foo)->check(CLI::Number.active(false));
     app.validate_positionals();
     args = {"1", "param1"};
     run();
@@ -1087,10 +1088,12 @@ TEST_F(TApp, PositionalValidation) {
     EXPECT_EQ(foo, "param1");
 
     args = {"param1", "1"};
-    run();
+    EXPECT_NO_THROW(run());
 
     EXPECT_EQ(options, "1");
     EXPECT_EQ(foo, "param1");
+
+    EXPECT_NE(app.get_option("bar")->get_validator("valbar"), nullptr);
 }
 
 TEST_F(TApp, PositionalNoSpaceLong) {
@@ -1696,12 +1699,12 @@ TEST_F(TApp, VectorIndexedValidator) {
     run();
     EXPECT_EQ(4u, app.count("-v"));
     EXPECT_EQ(4u, vvec.size());
-    opt->check(CLI::Validator(CLI::PositiveNumber).application_index(0));
+    opt->check(CLI::PositiveNumber.application_index(0));
     opt->check((!CLI::PositiveNumber).application_index(1));
     EXPECT_NO_THROW(run());
     EXPECT_EQ(4u, vvec.size());
     // v[3] would be negative
-    opt->check(CLI::Validator(CLI::PositiveNumber).application_index(3));
+    opt->check(CLI::PositiveNumber.application_index(3));
     EXPECT_THROW(run(), CLI::ValidationError);
 }
 

tests/HelpTest.cpp

@@ -798,6 +798,16 @@ TEST(THelp, ValidatorsText) {
     EXPECT_THAT(help, HasSubstr("UINT:INT in [0 - 12]")); // Loses UINT
 }
 
+TEST(THelp, ValidatorsTextCustom) {
+    CLI::App app;
+
+    std::string filename;
+    app.add_option("--f1", filename)->check(CLI::ExistingFile.description("Existing file"));
+
+    std::string help = app.help();
+    EXPECT_THAT(help, HasSubstr("Existing file"));
+}
+
 TEST(THelp, ValidatorsNonPathText) {
     CLI::App app;