util: fix parseEnv handling of invalid lines

src/node_dotenv.cc

@@ -134,13 +134,24 @@ void Dotenv::ParseContent(const std::string_view input) {
       auto newline = content.find('\n');
       if (newline != std::string_view::npos) {
         content.remove_prefix(newline + 1);
+        content = trim_spaces(content);
         continue;
+      } else {
+        break;
       }
     }
 
-    // If there is no equal character, then ignore everything
+    // Find the next equals sign and newline
     auto equal = content.find('=');
-    if (equal == std::string_view::npos) {
+    auto newline = content.find('\n');
+
+    // If there is no equal character in this line, skip to next line
+    if (equal == std::string_view::npos || (newline != std::string_view::npos && equal > newline)) {
+      if (newline != std::string_view::npos) {
+        content.remove_prefix(newline + 1);
+        content = trim_spaces(content);
+        continue;
+      }
       break;
     }
 
@@ -150,12 +161,19 @@ void Dotenv::ParseContent(const std::string_view input) {
     content = trim_spaces(content);
 
     if (key.empty()) {
+      // Skip invalid empty key
+      if (newline != std::string_view::npos) {
+        content.remove_prefix(newline + 1);
+        content = trim_spaces(content);
+        continue;
+      }
       break;
     }
 
     // Remove export prefix from key
     if (key.starts_with("export ")) {
       key.remove_prefix(7);
+      key = trim_spaces(key);
     }
 
     // SAFETY: Content is guaranteed to have at least one character

test/fixtures/dotenv/invalid-syntax.env

@@ -0,0 +1,8 @@
+foo
+
+bar
+baz=whatever
+VALID_AFTER_INVALID=test
+multiple_invalid
+lines_without_equals
+ANOTHER_VALID=value

test/parallel/test-dotenv-invalid-syntax.js

@@ -0,0 +1,71 @@
+// Flags: --env-file test/fixtures/dotenv/invalid-syntax.env
+'use strict';
+
+require('../common');
+const assert = require('node:assert');
+const { parseEnv } = require('node:util');
+
+// Test direct parseEnv usage
+{
+  const input = `foo
+
+bar
+baz=whatever
+VALID_AFTER_INVALID=test
+multiple_invalid
+lines_without_equals
+ANOTHER_VALID=value`;
+
+  const result = parseEnv(input);
+
+  // Using individual assertions for better error messages
+  assert.strictEqual(Object.keys(result).length, 3, 'Should only have 3 valid entries');
+  assert.strictEqual(result.baz, 'whatever', 'baz should have value "whatever"');
+  assert.strictEqual(result.VALID_AFTER_INVALID, 'test', 'VALID_AFTER_INVALID should have value "test"');
+  assert.strictEqual(result.ANOTHER_VALID, 'value', 'ANOTHER_VALID should have value "value"');
+
+  // Ensure invalid entries are not present
+  assert.strictEqual(result.foo, undefined, 'foo should not be present');
+  assert.strictEqual(result.bar, undefined, 'bar should not be present');
+  assert.strictEqual(result.multiple_invalid, undefined, 'multiple_invalid should not be present');
+  assert.strictEqual(result.lines_without_equals, undefined, 'lines_without_equals should not be present');
+}
+
+// Test edge cases
+{
+  const edgeCases = [
+    // Empty file
+    {
+      input: '\n\n  \n    ',
+      expected: {}
+    },
+    // Only invalid lines
+    {
+      input: 'no_equals_here\nanother_invalid_line\n  just_text',
+      expected: {}
+    },
+    // Mixed valid and invalid
+    {
+      input: 'VALID1=value1\ninvalid\nVALID2=value2',
+      expected: {
+        VALID1: 'value1',
+        VALID2: 'value2'
+      }
+    },
+    // Lines with spaces but no equals
+    {
+      input: '   spaces   \nVALID=value\n  more  spaces  ',
+      expected: {
+        VALID: 'value'
+      }
+    }
+  ];
+
+  for (const { input, expected } of edgeCases) {
+    assert.deepStrictEqual(
+      parseEnv(input),
+      expected,
+      `Failed parsing: ${JSON.stringify(input)}`
+    );
+  }
+}