class Inspector

class Inspector {
    
    /**
     * Asserts argument can be traversed with foreach.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed with foreach.
     */
    public static function assertTraversable($traversable) {
        return is_array($traversable) || $traversable instanceof \Traversable;
    }
    
    /**
     * Asserts callback returns TRUE for each member of a traversable.
     *
     * This is less memory intensive than using array_filter() to build a second
     * array and then comparing the arrays. Many of the other functions in this
     * collection alias this function passing a specific callback to make the
     * code more readable.
     *
     * @param callable $callable
     *   Callback function.
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and $callable returns TRUE on
     *   all members.
     *
     * @see http://php.net/manual/language.types.callable.php
     */
    public static function assertAll(callable $callable, $traversable) {
        if (static::assertTraversable($traversable)) {
            foreach ($traversable as $member) {
                if (!$callable($member)) {
                    return FALSE;
                }
            }
            return TRUE;
        }
        return FALSE;
    }
    
    /**
     * Asserts that all members are strings.
     *
     * Use this only if it is vital that the members not be objects, otherwise
     * test with ::assertAllStringable().
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are strings.
     */
    public static function assertAllStrings($traversable) {
        return static::assertAll('is_string', $traversable);
    }
    
    /**
     * Asserts all members are strings or objects with magic __toString() method.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are strings or
     *   objects with __toString().
     */
    public static function assertAllStringable($traversable) {
        if (static::assertTraversable($traversable)) {
            foreach ($traversable as $member) {
                if (!static::assertStringable($member)) {
                    return FALSE;
                }
            }
            return TRUE;
        }
        return FALSE;
    }
    
    /**
     * Asserts argument is a string or an object castable to a string.
     *
     * Use this instead of is_string() alone unless the argument being an object
     * in any way will cause a problem.
     *
     * @param mixed $string
     *   Variable to be examined
     *
     * @return bool
     *   TRUE if $string is a string or an object castable to a string.
     */
    public static function assertStringable($string) {
        return is_string($string) || is_object($string) && method_exists($string, '__toString');
    }
    
    /**
     * Asserts that all members are arrays.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are arrays.
     */
    public static function assertAllArrays($traversable) {
        return static::assertAll('is_array', $traversable);
    }
    
    /**
     * Asserts that the array is strict.
     *
     * What PHP calls arrays are more formally called maps in most other
     * programming languages. A map is a datatype that associates values to keys.
     * The term 'strict array' here refers to a 0-indexed array in the classic
     * sense found in programming languages other than PHP.
     *
     * @param mixed $array
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable is a 0-indexed array.
     *
     * @see http://php.net/manual/language.types.array.php
     */
    public static function assertStrictArray($array) {
        if (!is_array($array)) {
            return FALSE;
        }
        $i = 0;
        foreach (array_keys($array) as $key) {
            if ($i !== $key) {
                return FALSE;
            }
            $i++;
        }
        return TRUE;
    }
    
    /**
     * Asserts all members are strict arrays.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are strict arrays.
     *
     * @see ::assertStrictArray
     */
    public static function assertAllStrictArrays($traversable) {
        return static::assertAll([
            __CLASS__,
            'assertStrictArray',
        ], $traversable);
    }
    
    /**
     * Asserts all given keys exist in every member array.
     *
     * Drupal has several data structure arrays that require certain keys be set.
     * You can overload this function to specify a list of required keys. All
     * of the keys must be set for this method to return TRUE.
     *
     * As an example, this assertion tests for the keys of a theme registry.
     *
     * @code
     *   assert(Inspector::assertAllHaveKey(
     *     $arrayToTest, "type", "theme path", "function", "template", "variables", "render element", "preprocess functions"));
     * @endcode
     *
     * Note: If a method requires certain keys to be present it will usually be
     * specific about the data types for the values of those keys. Therefore it
     * will be best to write a specific test for it. Such tests are either bound
     * to the object that uses them, or are collected into one assertion set for
     * the package.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     * @param string ...
     *   Keys to be searched for.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members have all keys.
     */
    public static function assertAllHaveKey($traversable) {
        $args = func_get_args();
        unset($args[0]);
        if (static::assertTraversable($traversable)) {
            foreach ($traversable as $member) {
                foreach ($args as $key) {
                    if (!array_key_exists($key, $member)) {
                        return FALSE;
                    }
                }
            }
            return TRUE;
        }
        return FALSE;
    }
    
    /**
     * Asserts that all members are integer values.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are integers.
     */
    public static function assertAllIntegers($traversable) {
        return static::assertAll('is_int', $traversable);
    }
    
    /**
     * Asserts that all members are float values.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are floating point
     *   numbers.
     */
    public static function assertAllFloat($traversable) {
        return static::assertAll('is_float', $traversable);
    }
    
    /**
     * Asserts that all members are callable.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are callable.
     */
    public static function assertAllCallable($traversable) {
        return static::assertAll('is_callable', $traversable);
    }
    
    /**
     * Asserts that all members are not empty.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members not empty.
     */
    public static function assertAllNotEmpty($traversable) {
        if (static::assertTraversable($traversable)) {
            foreach ($traversable as $member) {
                if (empty($member)) {
                    return FALSE;
                }
            }
            return TRUE;
        }
        return FALSE;
    }
    
    /**
     * Asserts all members are numeric data types or strings castable to such.
     *
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are numeric.
     */
    public static function assertAllNumeric($traversable) {
        return static::assertAll('is_numeric', $traversable);
    }
    
    /**
     * Asserts that all members are strings that contain the specified string.
     *
     * This runs faster than the regular expression equivalent.
     *
     * @param string $pattern
     *   The needle to find.
     * @param mixed $traversable
     *   Variable to examine.
     * @param bool $case_sensitive
     *   TRUE to use strstr(), FALSE to use stristr() which is case insensitive.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are strings
     *   containing $pattern.
     */
    public static function assertAllMatch($pattern, $traversable, $case_sensitive = FALSE) {
        if (static::assertTraversable($traversable)) {
            if ($case_sensitive) {
                foreach ($traversable as $member) {
                    if (!(is_string($member) && strstr($member, $pattern))) {
                        return FALSE;
                    }
                }
            }
            else {
                foreach ($traversable as $member) {
                    if (!(is_string($member) && stristr($member, $pattern))) {
                        return FALSE;
                    }
                }
            }
            return TRUE;
        }
        return FALSE;
    }
    
    /**
     * Asserts that all members are strings matching a regular expression.
     *
     * @param string $pattern
     *   Regular expression string to find.
     * @param mixed $traversable
     *   Variable to be examined.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are strings
     *   matching $pattern.
     */
    public static function assertAllRegularExpressionMatch($pattern, $traversable) {
        if (static::assertTraversable($traversable)) {
            foreach ($traversable as $member) {
                if (!is_string($member)) {
                    return FALSE;
                }
                if (!preg_match($pattern, $member)) {
                    return FALSE;
                }
            }
            return TRUE;
        }
        return FALSE;
    }
    
    /**
     * Asserts that all members are objects.
     *
     * When testing if a collection is composed of objects those objects should
     * be given a common interface to implement and the test should be written to
     * search for just that interface. While this method will allow tests for
     * just object status or for multiple classes and interfaces this was done to
     * allow tests to be written for existing code without altering it. Only use
     * this method in that manner when testing code from third party vendors.
     *
     * Here are some examples:
     * @code
     *   // Just test all are objects, like a cache.
     *   assert(Inspector::assertAllObjects($collection));
     *
     *   // Test if traversable objects (arrays won't pass this)
     *   assert(Inspector::assertAllObjects($collection, '\\Traversable'));
     *
     *   // Test for the Foo class or Bar\None interface
     *   assert(Inspector::assertAllObjects($collection, '\\Foo', '\\Bar\\None'));
     * @endcode
     *
     * @param mixed $traversable
     *   Variable to be examined.
     * @param string ...
     *   Classes and interfaces to test objects against.
     *
     * @return bool
     *   TRUE if $traversable can be traversed and all members are objects with
     *   at least one of the listed classes or interfaces.
     */
    public static function assertAllObjects($traversable) {
        $args = func_get_args();
        unset($args[0]);
        if (static::assertTraversable($traversable)) {
            foreach ($traversable as $member) {
                if (count($args) > 0) {
                    foreach ($args as $instance) {
                        if ($member instanceof $instance) {
                            // We're continuing to the next member on the outer loop.
                            // @see http://php.net/continue
                            continue 2;
                        }
                    }
                    return FALSE;
                }
                elseif (!is_object($member)) {
                    return FALSE;
                }
            }
            return TRUE;
        }
        return FALSE;
    }

}