feat(stringify): header as comment

adaltas#419
bluelovers · Feb 12, 2024 · ddfeac1 · ddfeac1
1 parent 28088bc
commit ddfeac1
Show file tree

Hide file tree

Showing 3 changed files with 33 additions and 0 deletions.
diff --git a/packages/csv-stringify/lib/api/index.js b/packages/csv-stringify/lib/api/index.js
@@ -226,6 +226,9 @@ const stringifier = function(options, state, info){
         [err, headers] = this.stringify(headers);
       }
       if(err) return err;
+      if(this.options.header_as_comment){
+        headers = this.options.comment + ' ' + headers;
+      }
       push(headers);
     },
     __cast: function(value, context){

diff --git a/packages/csv-stringify/lib/api/normalize_options.js b/packages/csv-stringify/lib/api/normalize_options.js
@@ -109,6 +109,28 @@ const normalize_options = function(opts) {
   }else{
     // todo
   }
+  // Normalize option `headers_as_comment`
+  if(!options.header_as_comment){
+    options.header_as_comment = false;
+  }else if(!options.comment?.length){
+    throw new CsvError('CSV_INVALID_OPTION_COMMENT', [
+      'Invalid option comment:',
+      'comment must be a non empty string or buffer when enable header_as_comment,',
+      `got ${JSON.stringify(options.comment)}`
+    ], options);
+  }else{
+    if(Buffer.isBuffer(options.comment)){
+      options.comment = options.comment.toString();
+    }
+    if(typeof options.comment !== 'string'){
+      throw new CsvError('CSV_INVALID_OPTION_COMMENT', [
+        'Invalid option comment:',
+        'comment must be a buffer or a string when enable header_as_comment,',
+        `got ${JSON.stringify(options.comment)}`
+      ], options);
+    }
+    options.header = true;
+  }
   // Normalize option `columns`
   const [errColumns, columns] = normalize_columns(options.columns);
   if(errColumns !== undefined) return [errColumns];

diff --git a/packages/csv-stringify/lib/index.d.ts b/packages/csv-stringify/lib/index.d.ts
@@ -78,6 +78,14 @@ export interface Options extends stream.TransformOptions {
      * Display the column names on the first line if the columns option is provided or discovered.
      */
     header?: boolean
+    /**
+     * Display the column names on the first line as comment if the columns option is provided or discovered.
+     */
+    header_as_comment?: boolean
+    /**
+     * Treat all the characters after this one as a comment, default to '' (disabled).
+     */
+    comment?: string;
     /**
      * The quote characters, defaults to the ", an empty quote value will preserve the original field.
      */