PrefixAllGlobals: verify that namespace names use a prefix

Until now, namespaced classes, functions and constants would be exempt from the "prefix all globals" rule, but the namespace name _itself_ was not examined.

As namespace names can, of course, also conflict, the namespace name should be prefixed with a plugin/theme specific prefix.

This PR adds that feature to the sniff. The PR builds onto the changes made in PR 1491 and 1492.

Notes:
* The sniff allows for underscores and (other) non-word characters in a passed prefix to be converted to namespace separators when used in a namespace name.
    In other words, if a prefix of `my_plugin` is passed as the value of the custom property, a namespace name of `My\Plugin` will be accepted automatically.
* Passing a prefix property value containing namespace separators will now also be allowed and will no longer trigger a warning.

WordPress/Sniffs/NamingConventions/PrefixAllGlobalsSniff.php

@@ -20,6 +20,7 @@
  *
  * @since   0.12.0
  * @since   0.13.0 Class name changed: this class is now namespaced.
+ * @since   1.2.0  Now also checks whether namespaces are prefixed.
  *
  * @uses    \WordPress\Sniff::$custom_test_class_whitelist
  */
@@ -65,6 +66,20 @@ class PrefixAllGlobalsSniff extends AbstractFunctionParameterSniff {
 	 */
 	private $validated_prefixes = array();
 
+	/**
+	 * Target namespace prefixes after validation with regex indicator.
+	 *
+	 * All prefixes are lowercased for case-insensitive compare.
+	 * If the prefix doesn't already contain a namespace separator, but does contain
+	 * non-word characters, these will have been replaced with regex syntax to allow
+	 * for namespace separators and the `is_regex` indicator will have been set to `true`.
+	 *
+	 * @since 1.2.0
+	 *
+	 * @var array
+	 */
+	private $validated_namespace_prefixes = array();
+
 	/**
 	 * Cache of previously set prefixes.
 	 *
@@ -167,6 +182,7 @@ class PrefixAllGlobalsSniff extends AbstractFunctionParameterSniff {
 	 */
 	public function register() {
 		$targets = array(
+			\T_NAMESPACE  => \T_NAMESPACE,
 			\T_FUNCTION   => \T_FUNCTION,
 			\T_CLASS      => \T_CLASS,
 			\T_INTERFACE  => \T_INTERFACE,
@@ -274,6 +290,46 @@ public function process_token( $stackPtr ) {
 
 			return $this->process_variable_assignment( $stackPtr );
 
+		} elseif ( \T_NAMESPACE === $this->tokens[ $stackPtr ]['code'] ) {
+			$namespace_name = $this->get_declared_namespace_name( $stackPtr );
+
+			if ( false === $namespace_name || '' === $namespace_name || '\\' === $namespace_name ) {
+				return;
+			}
+
+			foreach ( $this->validated_namespace_prefixes as $key => $prefix_info ) {
+				if ( false === $prefix_info['is_regex'] ) {
+					if ( stripos( $namespace_name, $prefix_info['prefix'] ) === 0 ) {
+						$this->phpcsFile->recordMetric( $stackPtr, 'Prefix all globals: allowed prefixes', $key );
+						return;
+					}
+				} else {
+					// Ok, so this prefix should be used as a regex.
+					$regex = '`^' . $prefix_info['prefix'] . '`i';
+					if ( preg_match( $regex, $namespace_name ) > 0 ) {
+						$this->phpcsFile->recordMetric( $stackPtr, 'Prefix all globals: allowed prefixes', $key );
+						return;
+					}
+				}
+			}
+
+			// Still here ? In that case, we have a non-prefixed namespace name.
+			$recorded = $this->phpcsFile->addError(
+				self::ERROR_MSG,
+				$stackPtr,
+				'NonPrefixedNamespaceFound',
+				array(
+					'Namespaces declared',
+					$namespace_name,
+				)
+			);
+
+			if ( true === $recorded ) {
+				$this->record_potential_prefix_metric( $stackPtr, $namespace_name );
+			}
+
+			return;
+
 		} else {
 
 			// Namespaced methods, classes and constants do not need to be prefixed.
@@ -824,6 +880,7 @@ private function validate_prefixes() {
 		$this->previous_prefixes = $this->prefixes;
 
 		// Validate the passed prefix(es).
+		$ns_prefixes = array();
 		foreach ( $this->prefixes as $key => $prefix ) {
 			$prefixLC = strtolower( $prefix );
 
@@ -839,9 +896,9 @@ private function validate_prefixes() {
 			}
 
 			// Validate the prefix against characters allowed for function, class, constant names etc.
-			if ( preg_match( '`^[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*$`', $prefix ) !== 1 ) {
+			if ( preg_match( '`^[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff\\\\]*$`', $prefix ) !== 1 ) {
 				$this->phpcsFile->addWarning(
-					'The "%s" prefix is not a valid function/class/variable/constant prefix in PHP.',
+					'The "%s" prefix is not a valid namespace/function/class/variable/constant prefix in PHP.',
 					0,
 					'InvalidPrefixPassed',
 					array( $prefix )
@@ -851,10 +908,26 @@ private function validate_prefixes() {
 
 			// Lowercase the prefix to allow for direct compare.
 			$this->prefixes[ $key ] = $prefixLC;
+
+			/*
+			 * Replace non-word characters in the prefix with a regex snippet, but only if the
+			 * string doesn't already contain namespace separators.
+			 */
+			$is_regex = false;
+			if ( strpos( $prefix, '\\' ) === false && preg_match( '`[_\W]`', $prefix ) > 0 ) {
+				$prefix   = preg_replace( '`([_\W])`', '[\\\\\\\\$1]', $prefixLC );
+				$is_regex = true;
+			}
+
+			$ns_prefixes[ $prefixLC ] = array(
+				'prefix'   => $prefix,
+				'is_regex' => $is_regex,
+			);
 		}
 
-		// Set the validated prefixes cache.
-		$this->validated_prefixes = $this->prefixes;
+		// Set the validated prefixes caches.
+		$this->validated_prefixes           = $this->prefixes;
+		$this->validated_namespace_prefixes = $ns_prefixes;
 	}
 
 	/**

WordPress/Tests/NamingConventions/PrefixAllGlobalsUnitTest.1.inc

@@ -314,7 +314,7 @@ define( '\OtherNameSpace\PLUGIN_FILE', __FILE__ ); // OK.
 define( __NAMESPACE__ . '\PLUGIN_FILE', __FILE__ );
 define( '\PLUGIN_FILE', __FILE__ );
 
-namespace Testing {
+namespace TGMPA\Testing {
 	define( 'MY' . __NAMESPACE__, __FILE__ ); // Error, not actually namespaced.
 	define( 'MY\\' . __NAMESPACE__, __FILE__ ); // OK, even though strangely setup, the constant is in a namespace.
 }

WordPress/Tests/NamingConventions/PrefixAllGlobalsUnitTest.4.inc

@@ -0,0 +1,30 @@
+<?php
+// @codingStandardsChangeSetting WordPress.NamingConventions.PrefixAllGlobals prefixes acronym,tgmpa,test_this,test\that
+
+namespace TGMPA;
+
+namespace Acronym\B\C;
+
+namespace AcronymPlugin\B\C;
+
+namespace Test_This\C;
+
+namespace Test\This\C;
+
+namespace Test\That\C;
+
+namespace Test \ /* comment */ This \ C;
+
+namespace A\B\C; // Bad.
+
+use namespace\DEF; // Not our target.
+namespace\cname::method(); // Not our target.
+$acronym_result = namespace \ blah \ mine();  // Not our target.
+
+// @codingStandardsChangeSetting WordPress.NamingConventions.PrefixAllGlobals prefixes wordpress
+namespace wordpress\myplugin;
+
+// @codingStandardsChangeSetting WordPress.NamingConventions.PrefixAllGlobals prefixes wordpress\myplugin
+namespace wordpress\myplugin;
+
+// @codingStandardsChangeSetting WordPress.NamingConventions.PrefixAllGlobals prefixes false

WordPress/Tests/NamingConventions/PrefixAllGlobalsUnitTest.php

@@ -70,6 +70,12 @@ public function getErrorList( $testFile = 'PrefixAllGlobalsUnitTest.1.inc' ) {
 					403 => 1,
 				);
 
+			case 'PrefixAllGlobalsUnitTest.4.inc':
+				return array(
+					1  => 1, // 1 x error for blacklisted prefix passed.
+					18 => 1,
+				);
+
 			case 'PrefixAllGlobalsUnitTest.2.inc':
 				// Namespaced - all OK, fall through to the default case.
 			case 'PrefixAllGlobalsUnitTest.3.inc':
@@ -90,7 +96,7 @@ public function getWarningList( $testFile = 'PrefixAllGlobalsUnitTest.1.inc' ) {
 		switch ( $testFile ) {
 			case 'PrefixAllGlobalsUnitTest.1.inc':
 				return array(
-					1   => 3, // 3 x error for potentially incorrect prefix passed.
+					1   => 2, // 2 x warning for potentially incorrect prefix passed.
 					249 => 1,
 					250 => 1,
 					253 => 1,