set limit option to restrict total number of records

bin/view-csv

@@ -17,25 +17,32 @@ use Symfony\Component\Console\Style\SymfonyStyle;
 $command = (new SingleCommandApplication())
     ->addArgument('csvFile', InputArgument::REQUIRED, 'csv file name')
     ->addOption('hide-column', null, InputOption::VALUE_REQUIRED, 'Columns to hide (comma-separated)')
+    ->addOption('limit', null, InputOption::VALUE_REQUIRED, 'limit number of records')
     ->setCode(function (InputInterface $input, OutputInterface $output): int {
         $io = new SymfonyStyle($input, $output);
         $csvFile = $input->getArgument('csvFile');
-
         $hiddenColumns = $input->getOption('hide-column');
-
-        $hiddenColumnsArray = explode(',', $hiddenColumns);
+        $limit = $input->getOption('limit');
 
         if (!file_exists($csvFile)) {
             $io->error("{$csvFile} does not exists");
             return Command::FAILURE;
         }
 
+        if (isset($limit) && !is_numeric($limit)) {
+            $io->error("{$limit} is not numeric");
+            return Command::FAILURE;
+        }
+
+        $hiddenColumns = $hiddenColumns ? explode(',', $hiddenColumns) : false;
+        $limit = $limit ? (int)$limit : false;
+
         $serviceContainer = new ServiceContainer();
         /** @var CsvFileHandler $csvFileHandler */
         $csvFileHandler = $serviceContainer->getContainerBuilder()->get('csv_file_handler');
 
         try {
-            $data = $csvFileHandler->toArray($csvFile, $hiddenColumnsArray);
+            $data = $csvFileHandler->toArray($csvFile, $hiddenColumns, $limit);
         } catch (FileHandlerException) {
             $io->error('invalid csv file');
             return Command::FAILURE;

src/CsvFileHandler.php

@@ -53,13 +53,13 @@ public function toJson(string $filename): string|false
      * @return array<int,array<string,string>>
      * @throws FileHandlerException
      */
-    public function toArray(string $filename, array|false $hideColumns = false): array
+    public function toArray(string $filename, array|false $hideColumns = false, int|false $limit = false): array
     {
         if (!file_exists($filename)) {
             throw new FileHandlerException('file not found');
         }
 
-        return iterator_to_array($this->getRows($filename, $hideColumns));
+        return iterator_to_array($this->getRows($filename, $hideColumns, $limit));
     }
 
     public function findAndReplaceInCsv(
@@ -148,22 +148,22 @@ private function isValidCsvFileFormat(array $row): bool
     }
 
     /**
-     * @param array<string> $row
+     * @param array<string> $headers
      * @param array<string> $hideColumns
-     * @return array<int<0, max>,int|string>
+     * @return array<int<0, max>,int>
      */
-    private function setColumnsToHide(array &$row, array $hideColumns): array
+    private function setColumnsToHide(array &$headers, array $hideColumns): array
     {
         $indices = [];
         if (!empty($hideColumns)) {
             foreach ($hideColumns as $hideColumn) {
-                $index = array_search($hideColumn, $row);
+                $index = array_search($hideColumn, $headers);
                 if ($index !== false) {
-                    $indices[] = $index;
-                    unset($row[$index]);
+                    $indices[] = (int)$index;
+                    unset($headers[$index]);
                 }
             }
-            $row = array_values($row);
+            $headers = array_values($headers);
         }
         return $indices;
     }
@@ -174,7 +174,7 @@ private function setColumnsToHide(array &$row, array $hideColumns): array
      * @return Generator
      * @throws FileHandlerException
      */
-    private function getRows(string $filename, array|false $hideColumns = false): Generator
+    private function getRows(string $filename, array|false $hideColumns = false, int|false $limit = false): Generator
     {
         $csvFile = fopen($filename, 'r');
         if (!$csvFile) {
@@ -191,6 +191,7 @@ private function getRows(string $filename, array|false $hideColumns = false): Ge
 
 
         $isEmptyFile = true;
+        $count = 0;
         try {
             while (($row = fgetcsv($csvFile)) !== false) {
                 $isEmptyFile = false;
@@ -199,18 +200,17 @@ private function getRows(string $filename, array|false $hideColumns = false): Ge
                 }
 
                 if (!empty($indices)) {
-                    foreach ($indices as $index) {
-                        if (isset($row[$index])) {
-                            unset($row[$index]);
-                        }
-                    }
-
-                    $row = array_values($row);
+                    $this->removeElementByIndex($row, $indices);
                 }
 
-                $item = array_combine($headers, $row);
 
+                $item = array_combine($headers, $row);
                 yield $item;
+                $count++;
+
+                if (is_int($limit) && $limit <= $count) {
+                    break;
+                }
             }
         } finally {
             fclose($csvFile);
@@ -222,6 +222,22 @@ private function getRows(string $filename, array|false $hideColumns = false): Ge
         }
     }
 
+    /**
+     * @param array<int,string> $row
+     * @param array<int<0, max>, int> $indices
+     * @return void
+     */
+    private function removeElementByIndex(array &$row, array $indices): void
+    {
+        foreach ($indices as $index) {
+            if (isset($row[$index])) {
+                unset($row[$index]);
+            }
+        }
+
+        $row = array_values($row);
+    }
+
     /**
      * @param array<string> $row
      * @param string $keyword

tests/Integration/ViewCsvCommandTest.php

@@ -62,9 +62,20 @@ public function viewCsvFileDisplayInformationCorrectly(string $file): void
         unlink($file);
     }
 
+    #[Test]
+    public function IfLimitIsSetToNonNumericCommandShouldFail(): void
+    {
+        $command = "php bin/view-csv movie.csv --limit hello";
+        exec($command, $output, $exitCode);
+        $actualOutput = implode("\n", $output);
+
+        $this->assertSame(1, $exitCode);
+        $this->assertStringContainsString("hello is not numeric", $actualOutput);
+    }
+
     #[Test]
     #[DataProvider('InvalidFileProvider')]
-    public function throwExceptionIfFileIsInvalid(string $file): void
+    public function commandShouldReturnErrorIfFileIsInvalid(string $file): void
     {
         $command = "php bin/view-csv {$file}";
         exec($command, $output, $exitCode);

tests/unit/CsvFileHandlerTest.php

@@ -125,6 +125,17 @@ public function toArrayMethodWithHideColumnsOptionReturnsValidArray(array $colum
         $this->assertEquals($expected, $data[0]);
     }
 
+    #[Test]
+    #[DataProvider('limitDataProvider')]
+    public function toArrayMethodShouldRestrictNumberOfRecordsWhenLimitIsSet(int $limit): void
+    {
+        $data = $this->csvFileHandler->toArray("movie.csv", ["Year"], $limit);
+
+        $count = count($data);
+
+        $this->assertSame($count, $limit);
+    }
+
     #[Test]
     public function searchByKeywordAndReturnArray(): void
     {
@@ -267,4 +278,14 @@ public static function columnsToHideDataProvider(): iterable
         yield [$hideSingleColumn, $expected1];
         yield [$hideMultipleColumns, $expected2];
     }
+
+    /**
+     * max limit for the test file is 3
+     * @return iterable<array<int>>
+     */
+    public static function limitDataProvider(): iterable
+    {
+        yield [1];
+        yield [2];
+    }
 }