diff --git a/lib/config/parse.ts b/lib/config/parse.ts
new file mode 100644
index 00000000000000..45bbb8e651d434
--- /dev/null
+++ b/lib/config/parse.ts
@@ -0,0 +1,75 @@
+import jsonValidator from 'json-dup-key-validator';
+import JSON5 from 'json5';
+import upath from 'upath';
+import { logger } from '../logger';
+import { parseJson } from '../util/common';
+
+export function parseFileConfig(
+  fileName: string,
+  fileContents: string,
+):
+  | { success: true; parsedContents: unknown }
+  | { success: false; validationError: string; validationMessage: string } {
+  const fileType = upath.extname(fileName);
+
+  if (fileType === '.json5') {
+    try {
+      return { success: true, parsedContents: JSON5.parse(fileContents) };
+    } catch (err) /* istanbul ignore next */ {
+      logger.debug({ fileName, fileContents }, 'Error parsing JSON5 file');
+      const validationError = 'Invalid JSON5 (parsing failed)';
+      const validationMessage = `JSON5.parse error: \`${err.message.replaceAll(
+        '`',
+        "'",
+      )}\``;
+      return {
+        success: false,
+        validationError,
+        validationMessage,
+      };
+    }
+  } else {
+    let allowDuplicateKeys = true;
+    let jsonValidationError = jsonValidator.validate(
+      fileContents,
+      allowDuplicateKeys,
+    );
+    if (jsonValidationError) {
+      const validationError = 'Invalid JSON (parsing failed)';
+      const validationMessage = jsonValidationError;
+      return {
+        success: false,
+        validationError,
+        validationMessage,
+      };
+    }
+    allowDuplicateKeys = false;
+    jsonValidationError = jsonValidator.validate(
+      fileContents,
+      allowDuplicateKeys,
+    );
+    if (jsonValidationError) {
+      const validationError = 'Duplicate keys in JSON';
+      const validationMessage = JSON.stringify(jsonValidationError);
+      return {
+        success: false,
+        validationError,
+        validationMessage,
+      };
+    }
+    try {
+      return {
+        success: true,
+        parsedContents: parseJson(fileContents, fileName),
+      };
+    } catch (err) /* istanbul ignore next */ {
+      logger.debug({ fileContents }, 'Error parsing renovate config');
+      const validationError = 'Invalid JSON (parsing failed)';
+      const validationMessage = `JSON.parse error:  \`${err.message.replaceAll(
+        '`',
+        "'",
+      )}\``;
+      return { success: false, validationError, validationMessage };
+    }
+  }
+}
diff --git a/lib/workers/repository/init/merge.ts b/lib/workers/repository/init/merge.ts
index f5acc402f63de3..c8ced5681b9e3a 100644
--- a/lib/workers/repository/init/merge.ts
+++ b/lib/workers/repository/init/merge.ts
@@ -1,12 +1,10 @@
 import is from '@sindresorhus/is';
-import jsonValidator from 'json-dup-key-validator';
-import JSON5 from 'json5';
-import upath from 'upath';
 import { mergeChildConfig } from '../../../config';
 import { configFileNames } from '../../../config/app-strings';
 import { decryptConfig } from '../../../config/decrypt';
 import { migrateAndValidate } from '../../../config/migrate-validate';
 import { migrateConfig } from '../../../config/migration';
+import { parseFileConfig } from '../../../config/parse';
 import * as presets from '../../../config/presets';
 import { applySecretsToConfig } from '../../../config/secrets';
 import type { RenovateConfig } from '../../../config/types';
@@ -131,71 +129,18 @@ export async function detectRepoFileConfig(): Promise<RepoFileConfig> {
       configFileRaw = '{}';
     }
 
-    const fileType = upath.extname(configFileName);
+    const parseResult = parseFileConfig(configFileName, configFileRaw);
 
-    if (fileType === '.json5') {
-      try {
-        configFileParsed = JSON5.parse(configFileRaw);
-      } catch (err) /* istanbul ignore next */ {
-        logger.debug(
-          { renovateConfig: configFileRaw },
-          'Error parsing renovate config renovate.json5',
-        );
-        const validationError = 'Invalid JSON5 (parsing failed)';
-        const validationMessage = `JSON5.parse error: \`${err.message.replaceAll(
-          '`',
-          "'",
-        )}\``;
-        return {
-          configFileName,
-          configFileParseError: { validationError, validationMessage },
-        };
-      }
-    } else {
-      let allowDuplicateKeys = true;
-      let jsonValidationError = jsonValidator.validate(
-        configFileRaw,
-        allowDuplicateKeys,
-      );
-      if (jsonValidationError) {
-        const validationError = 'Invalid JSON (parsing failed)';
-        const validationMessage = jsonValidationError;
-        return {
-          configFileName,
-          configFileParseError: { validationError, validationMessage },
-        };
-      }
-      allowDuplicateKeys = false;
-      jsonValidationError = jsonValidator.validate(
-        configFileRaw,
-        allowDuplicateKeys,
-      );
-      if (jsonValidationError) {
-        const validationError = 'Duplicate keys in JSON';
-        const validationMessage = JSON.stringify(jsonValidationError);
-        return {
-          configFileName,
-          configFileParseError: { validationError, validationMessage },
-        };
-      }
-      try {
-        configFileParsed = parseJson(configFileRaw, configFileName);
-      } catch (err) /* istanbul ignore next */ {
-        logger.debug(
-          { renovateConfig: configFileRaw },
-          'Error parsing renovate config',
-        );
-        const validationError = 'Invalid JSON (parsing failed)';
-        const validationMessage = `JSON.parse error:  \`${err.message.replaceAll(
-          '`',
-          "'",
-        )}\``;
-        return {
-          configFileName,
-          configFileParseError: { validationError, validationMessage },
-        };
-      }
+    if (!parseResult.success) {
+      return {
+        configFileName,
+        configFileParseError: {
+          validationError: parseResult.validationError,
+          validationMessage: parseResult.validationMessage,
+        },
+      };
     }
+    configFileParsed = parseResult.parsedContents;
     logger.debug(
       { fileName: configFileName, config: configFileParsed },
       'Repository config',