From 1fc3d7538ec4a39d03736369323ac41c710bdbfb Mon Sep 17 00:00:00 2001
From: Greg Anderson <greg.1.anderson@greenknowe.org>
Date: Sat, 30 Mar 2024 06:35:19 -0700
Subject: [PATCH] Make table headers optional when table is empty (#108)

* Add TABLE_EMPTY_MESSAGE formatter option to allow caller to control whether or not table headers should be emitted when the table is empty

* Oh, Windows.

* Update tests/FormattersTest.php

Co-authored-by: Moshe Weitzman <weitzman@tejasa.com>

---------

Co-authored-by: Moshe Weitzman <weitzman@tejasa.com>
---
 src/Formatters/TableFormatter.php | 11 +++++++++++
 src/Options/FormatterOptions.php  |  6 ++++++
 tests/FormattersTest.php          | 29 +++++++++++++++++++++++++++++
 3 files changed, 46 insertions(+)

diff --git a/src/Formatters/TableFormatter.php b/src/Formatters/TableFormatter.php
index b808e92..bdc29c3 100644
--- a/src/Formatters/TableFormatter.php
+++ b/src/Formatters/TableFormatter.php
@@ -73,6 +73,7 @@ public function write(OutputInterface $output, $tableTransformer, FormatterOptio
         $defaults = [
             FormatterOptions::TABLE_STYLE => 'consolidation',
             FormatterOptions::INCLUDE_FIELD_LABELS => true,
+            FormatterOptions::TABLE_EMPTY_MESSAGE => false,
         ];
 
         $table = new Table($output);
@@ -83,10 +84,20 @@ public function write(OutputInterface $output, $tableTransformer, FormatterOptio
         $isList = $tableTransformer->isList();
         $includeHeaders = $options->get(FormatterOptions::INCLUDE_FIELD_LABELS, $defaults);
         $listDelimiter = $options->get(FormatterOptions::LIST_DELIMITER, $defaults);
+        $emptyMessage = $options->get(FormatterOptions::TABLE_EMPTY_MESSAGE, $defaults);
 
         $headers = $tableTransformer->getHeaders();
         $data = $tableTransformer->getTableData($includeHeaders && $isList);
 
+        // Do not print table headers for an empty table if the
+        // TABLE_EMPTY_MESSAGE has been set.
+        if (empty($data) && ($emptyMessage !== false)) {
+            if (!empty($emptyMessage)) {
+                $output->writeln($emptyMessage);
+            }
+            return;
+        }
+
         if ($listDelimiter) {
             if (!empty($headers)) {
                 array_splice($headers, 1, 0, ':');
diff --git a/src/Options/FormatterOptions.php b/src/Options/FormatterOptions.php
index d47408b..a1c85a4 100644
--- a/src/Options/FormatterOptions.php
+++ b/src/Options/FormatterOptions.php
@@ -38,6 +38,7 @@ class FormatterOptions
     const FORMAT = 'format';
     const DEFAULT_FORMAT = 'default-format';
     const TABLE_STYLE = 'table-style';
+    const TABLE_EMPTY_MESSAGE = 'table-empty-message';
     const LIST_ORIENTATION = 'list-orientation';
     const FIELDS = 'fields';
     const FIELD = 'field';
@@ -137,6 +138,11 @@ public function setFieldLabels($fieldLabels)
         return $this->setConfigurationValue(self::FIELD_LABELS, $fieldLabels);
     }
 
+    public function setTableEmptyMessage($emptyMessage)
+    {
+        return $this->setConfigurationValue(FormatterOptions::TABLE_EMPTY_MESSAGE, $emptyMessage);
+    }
+
     public function setDefaultStringField($defaultStringField)
     {
         return $this->setConfigurationValue(self::DEFAULT_STRING_FIELD, $defaultStringField);
diff --git a/tests/FormattersTest.php b/tests/FormattersTest.php
index cff3ee5..5f365ab 100644
--- a/tests/FormattersTest.php
+++ b/tests/FormattersTest.php
@@ -934,6 +934,35 @@ function testTableWithMissingCell()
         $this->assertFormattedOutputMatches($expectedTsvWithHeaders, 'tsv', $data, new FormatterOptions(), ['include-field-labels' => true]);
     }
 
+    function testEmptyTable()
+    {
+        if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
+            $this->markTestSkipped("Once again we are having spurious failures on this test under Windows. In theory it should work.");
+        }
+
+        $options = new FormatterOptions();
+        $options->setWidth(42);
+        $options->setFieldLabels(['first' => 'First', 'second' => 'Second']);
+
+        $data = new RowsOfFields([]);
+
+        $expected = <<<EOT
+------- --------
+First   Second
+------- --------
+EOT;
+
+        $this->assertFormattedOutputMatches($expected, 'table', $data, $options);
+
+        $expected = <<<EOT
+Does not have any headers
+EOT;
+
+        $options->setTableEmptyMessage("Does not have any headers");
+
+        $this->assertFormattedOutputMatches($expected, 'table', $data, $options);
+    }
+
     /**
      * @test
      * @return void