test: add test case

Author: rayark1

src/node_dotenv.cc

@@ -147,10 +147,13 @@ void Dotenv::ParseContent(const std::string_view input) {
     if (equal == std::string_view::npos) {
       auto newline = content.find('\n');
       if (newline != std::string_view::npos) {
+        // If we used `newline` only, 
+        // the '\n' might remain and cause an empty-line parse
         content.remove_prefix(newline + 1);
       } else {
         content = {};
       }
+      // No valid data here, skip to next line
       continue;
     }
 
@@ -234,10 +237,12 @@ void Dotenv::ParseContent(const std::string_view input) {
         // since there could be newline characters inside the value.
         auto newline = content.find('\n', closing_quote + 1);
         if (newline != std::string_view::npos) {
+           // Use +1 to discard the '\n' itself => next line
           content.remove_prefix(newline + 1);
         } else {
           content = {};
         }
+        // No valid data here, skip to next line
         continue;
       }
     } else {

test/fixtures/dotenv/valid.env

@@ -7,6 +7,7 @@ BASIC=basic
 # previous line intentionally left blank
 AFTER_LINE=after_line
 A="B=C"
+B=C=D
 EMPTY=
 EMPTY_SINGLE_QUOTES=''
 EMPTY_DOUBLE_QUOTES=""

test/parallel/test-dotenv.js

@@ -83,3 +83,4 @@ assert.strictEqual(process.env.EXPORT_EXAMPLE, 'ignore export');
 // Ignore spaces before double quotes to avoid quoted strings as value
 assert.strictEqual(process.env.SPACE_BEFORE_DOUBLE_QUOTES, 'space before double quotes');
 assert.strictEqual(process.env.A, 'B=C');
+assert.strictEqual(process.env.B, 'C=D');

test/parallel/test-util-parse-env.js

@@ -12,6 +12,7 @@ const fs = require('node:fs');
 
   assert.deepStrictEqual(util.parseEnv(validContent), {
     A: 'B=C',
+    B: 'C=D',
     AFTER_LINE: 'after_line',
     BACKTICKS: 'backticks',
     BACKTICKS_INSIDE_DOUBLE: '`backticks` work inside double quotes',