Merge param descriptions when adding or updating types

src/Psalm/Internal/FileManipulation/FunctionDocblockManipulator.php

@@ -17,7 +17,9 @@
 use function array_key_exists;
 use function array_merge;
 use function array_reduce;
+use function array_slice;
 use function count;
+use function implode;
 use function is_string;
 use function ltrim;
 use function preg_match;
@@ -332,7 +334,29 @@ private function getDocblock(): string
                 foreach ($parsed_docblock->tags['param'] as &$param_block) {
                     $doc_parts = CommentAnalyzer::splitDocLine($param_block);
 
+                    // If there's no type
+                    if (($doc_parts[0] ?? null) === '$' . $param_name) {
+                        // If the parameter has a description add that back
+                        if (count($doc_parts) > 1) {
+                            $new_param_block .= " ". implode(" ", array_slice($doc_parts, 1));
+                        }
+
+                        if ($param_block !== $new_param_block) {
+                            $modified_docblock = true;
+                        }
+
+                        $param_block = $new_param_block;
+                        $found_in_params = true;
+                        break;
+                    }
+
+                    // If there is a type
                     if (($doc_parts[1] ?? null) === '$' . $param_name) {
+                        // If the parameter has a description add that back
+                        if (count($doc_parts) > 2) {
+                            $new_param_block .= " ". implode(" ", array_slice($doc_parts, 2));
+                        }
+
                         if ($param_block !== $new_param_block) {
                             $modified_docblock = true;
                         }

tests/FileManipulation/ParamTypeManipulationTest.php

@@ -26,6 +26,25 @@ function foo(string $s): string {
                 'issues_to_fix' => ['MismatchingDocblockParamType'],
                 'safe_types' => true,
             ],
+            'fixMismatchingDocblockWithDescriptionParamType70' => [
+                'input' => '<?php
+                    /**
+                     * @param int $s the string
+                     */
+                    function foo(string $s): string {
+                        return "hello";
+                    }',
+                'output' => '<?php
+                    /**
+                     * @param string $s the string
+                     */
+                    function foo(string $s): string {
+                        return "hello";
+                    }',
+                'php_version' => '7.0',
+                'issues_to_fix' => ['MismatchingDocblockParamType'],
+                'safe_types' => true,
+            ],
             'fixNamespacedMismatchingDocblockParamsType70' => [
                 'input' => '<?php
                     namespace Foo\Bar {
@@ -139,6 +158,39 @@ function callsWithString($a): void {
                 'issues_to_fix' => ['MissingParamType'],
                 'safe_types' => true,
             ],
+            'noStringParamTypeWithDocblockAndDescriptionCall' => [
+                'input' => '<?php
+                    class C {
+                        /**
+                         * @param $ab the string you pass in
+                         */
+                        public function fooFoo($ab): void {}
+                    }
+
+                    /**
+                     * @param string $ab
+                     */
+                    function callsWithString($ab): void {
+                        (new C)->fooFoo($ab);
+                    }',
+                'output' => '<?php
+                    class C {
+                        /**
+                         * @param string $ab the string you pass in
+                         */
+                        public function fooFoo($ab): void {}
+                    }
+
+                    /**
+                     * @param string $ab
+                     */
+                    function callsWithString($ab): void {
+                        (new C)->fooFoo($ab);
+                    }',
+                'php_version' => '7.1',
+                'issues_to_fix' => ['MissingParamType'],
+                'safe_types' => true,
+            ],
             'noStringParamType56' => [
                 'input' => '<?php
                     class C {