Add some tests + phpdoc

src/Fits.php

@@ -19,6 +19,8 @@ class Fits
     public readonly string $imageBlob;
 
     /**
+    * Construct a Fits object
+    * @param string $path The full path to the FITS file
     * @throws InvalidFits, InvalidPath
     * @todo Check path for reading/writing errors
     */
@@ -36,6 +38,7 @@ class Fits
         }
 
         $this->headerBlock = $this->extractHeader();
+
         $this->fitsHeader = new FitsHeader($this->headerBlock);
         $this->imageBlob = $this->extractImageBlob();
     }
@@ -67,6 +70,7 @@ class Fits
     */
     private function extractHeader(): string
     {
+        
         $end = strpos($this->contents, 'END');
         // Determine minimum integer number of blocks including 'END' position
         $headerEnd = (($end - ($end % 2880)) / 2880 + 1) * 2880;

src/FitsHeader.php

@@ -45,8 +45,10 @@ class FitsHeader
 
         foreach ($filtered as $record) {
             $splitByComment = explode('/', $record);
-            $comment = isset($splitByComment[1]) ? $splitByComment[1] : null;
-            [$name, $value] = explode('=', $splitByComment[0]);
+            $comment = $splitByComment[1] ?? null;
+            $keyVal = explode('=', $splitByComment[0]);
+            $name = $keyVal[0];
+            $value = $keyVal[1] ?? '';
 
             $keywords[] = new Keyword(
                 name : $name,
@@ -72,7 +74,7 @@ class FitsHeader
         return $keywordsString . $blanks;
     }
     /**
-    * Retrieve a Keyword object base on key name
+    * Retrieve a Keyword object based on key name
     */
     public function keyword(string $key): ?Keyword
     {

src/Keyword.php

@@ -12,7 +12,7 @@ readonly class Keyword
 {
     public function __construct(
         public string $name,
-        public string $value,
+        public ?string $value,
         public ?string $comment,
     ) {}