Fix YAML ScannerError on Windows credentials_path

src/adloop/cli.py

@@ -160,7 +160,12 @@ def _generate_config_yaml(
     if project_id:
         lines.append(f'  project_id: "{project_id}"')
     if credentials_path:
-        lines.append(f'  credentials_path: "{credentials_path}"')
+        # YAML treats `\` inside double-quoted strings as escape sequences (e.g.
+        # `\U` begins a Unicode escape, breaking Windows paths like `c:\Users\...`).
+        # Single-quoted strings are literal — backslashes are safe. Embedded
+        # single quotes (rare in paths) are escaped per YAML spec by doubling them.
+        escaped = credentials_path.replace("'", "''")
+        lines.append(f"  credentials_path: '{escaped}'")
     else:
         lines.append("  # Using built-in credentials (no credentials_path needed)")
     lines.append('  token_path: "~/.adloop/token.json"')

tests/test_cli.py

@@ -0,0 +1,56 @@
+"""Tests for the `adloop init` wizard helpers in `adloop.cli`."""
+
+from __future__ import annotations
+
+import yaml
+
+from adloop.cli import _generate_config_yaml
+
+
+class TestGenerateConfigYaml:
+    """YAML generation in the init wizard must produce parseable output."""
+
+    def _generate(self, **overrides):
+        defaults = {
+            "project_id": "",
+            "credentials_path": "",
+            "property_id": "123456789",
+            "developer_token": "abc123",
+            "customer_id": "123-456-7890",
+            "login_customer_id": "987-654-3210",
+            "max_daily_budget": 50.0,
+            "require_dry_run": True,
+        }
+        defaults.update(overrides)
+        return _generate_config_yaml(**defaults)
+
+    def test_windows_credentials_path_parses(self):
+        """Regression for Windows backslash paths breaking YAML parsing.
+
+        Previously the wizard wrote `credentials_path: "c:\\Users\\..."` which
+        YAML interpreted as a `\\U` Unicode escape sequence and raised
+        ScannerError. Single quotes treat backslashes literally.
+        """
+        win_path = r"c:\Users\user\.adloop\credentials.json"
+        text = self._generate(credentials_path=win_path)
+        parsed = yaml.safe_load(text)
+        assert parsed["google"]["credentials_path"] == win_path
+
+    def test_posix_credentials_path_parses(self):
+        posix_path = "/home/user/.adloop/credentials.json"
+        text = self._generate(credentials_path=posix_path)
+        parsed = yaml.safe_load(text)
+        assert parsed["google"]["credentials_path"] == posix_path
+
+    def test_path_with_embedded_apostrophe_parses(self):
+        """YAML single-quoted strings escape `'` by doubling — make sure we do."""
+        weird_path = r"c:\Users\o'brien\.adloop\credentials.json"
+        text = self._generate(credentials_path=weird_path)
+        parsed = yaml.safe_load(text)
+        assert parsed["google"]["credentials_path"] == weird_path
+
+    def test_no_credentials_path_uses_bundled_comment(self):
+        text = self._generate(credentials_path="")
+        assert "Using built-in credentials" in text
+        parsed = yaml.safe_load(text)
+        assert "credentials_path" not in parsed.get("google", {})