Resolve config internally

lib/config.js

@@ -1,4 +1,3 @@
-const { cosmiconfigSync } = require("cosmiconfig");
 const { isString, isNumber, isPlainObject } = require("is-what");
 const path = require("path");
 const pkg = require("../package.json");
@@ -56,16 +55,62 @@ function validateConfiguration(configuration) {
 }
 
 function resolveConfig() {
-  const explorer = cosmiconfigSync(pkg.name);
-  return explorer.search();
+  // const explorer = cosmiconfigSync(pkg.name);
+  // return explorer.search();
+  const key = pkg.name;
+  const result = {
+    config: undefined,
+    filepath: undefined,
+    isEmpty: true
+  };
+
+  const hostPkgPath = path.join(cwd, "package.json");
+  const hostPkg = require(hostPkgPath);
+  if (hostPkg.hasOwnProperty(key)) {
+    result.isEmpty = false;
+    result.config = hostPkg[key];
+    result.file = hostPkgPath;
+  }
+
+  if (result.isEmpty) {
+    const files = [
+      `.${key}rc`,
+      `.${key}rc.json`,
+      `.${key}rc.js`,
+      `${key}.config.js`
+    ];
+    let i = 0;
+    let fileName;
+    let filePath;
+    let config;
+
+    while (result.isEmpty && i < files.length) {
+      fileName = files[i++];
+      filePath = path.join(cwd, fileName);
+      config = require(filePath);
+      result.isEmpty = Boolean(file);
+    }
+
+    if (!result.isEmpty) {
+      result.file = filePath;
+      const isFunction = typeof config === "function";
+      result.config = isFunction ? config() : config;
+    }
+  }
+
+  if (!result.isEmpty) {
+    delete result.isEmpty;
+  }
+
+  return result;
 }
 
 function processConfiguration(customConfig) {
   const searchedConfig = resolveConfig();
   const configuration = Object.assign(
     {},
     defaults,
-    searchedConfig && searchedConfig.config,
+    searchedConfig.config,
     customConfig
   );