如何在angularjs中验证仅具有特殊字符的正则表达式？

Question

I have to do validation for particular text value. If string is empty, i have to return as please enter some value. The text field should allow alphanumeric and special characters .@_ .If user enter any other special character, need to return special characters except .@_ not allowed. And if they enter only special characters, i have to return 'do not enter special char'? I tried below method, but i did not work out. Any help pls?

Please see updated code here.

const test1 = '[^A-Za-z0-9_||@||\. ]';
const test2 = '[A-Za-z0-9]';
const whitespace = '/^\s*$/';
const onlyspecial = '/[.@_ ]/';

if(strval.match(whitespace))
{
    return "Please enter value";
}
if(strval.match(test1))
{
    if(strval.match(test2)|| strval.match(onlyspecial))
    {
        return "special character except @,space,underscore and . not allowed";
    }
    else
    {
        return "do not enter only special char";
    }
}

Results for various input:

strval = "abcd@123" - pass
strval = "abcd_123" - pass
strval= "abcd test" - pass
strval = "abcd.test - pass
strval = .@_   - do not enter only special char (though it is acceptable characters, only entering these should not accept)
strval = "abcd$%^" - special character except @,space,underscore and . not allowed
strval = "abcs2323&&" - special character except @,space,underscore and . not allowed
strval = "$$$%%^&&"  - do not enter only special char
strval = ".@_1234"  - please enter valid name

Answer 1

Replace console.log(...) with return it should work.

var strVal = 'Abcd';

const onlySpecial = /[@_.]/
const alphaNumeric = /[A-Za-z0-9]/
const alphaNumericSpecial = /[^A-Za-z0-9@_.]/

if (strVal == '') {
    console.log("Nop")
} else if (alphaNumericSpecial.test(strVal)) {
    console.log("Only Alphanumeric and @, _, .")
}

else {
    if (onlySpecial.test(strVal) && alphaNumeric.test(strVal)) {
    console.log("Good Character.")
    } else if (onlySpecial.test(strVal) && !alphaNumeric.test(strVal)) {
    console.log("Don't Enter only special character.")
    } else {
    console.log("Alphanumeric..")
    }
}

Answer 2

     const test1 = '[^A-Za-z0-9 \S||@||\.||_]';
     const test2 = '[A-Za-z0-9]';
     const whiteSpace = /^\s*$/;


      if (strValue.match(whiteSpace)){
           return "Please enter value";
      }else if (strValue.match(test1)) {
           return "Please enter valid name (except .@_ )";
      }else if (!strValue.match(test2)){
           return "Don't enter only special characters";
      }