fix: resolve aliased packages and packages that don't resolve their m…

…ain files

index.js

@@ -16,22 +16,47 @@ function resolvePackagePath(packageName, options) {
     .replace(trailingPathSepRegExp, "");
 }
 
+function tryFindPackagePath(packageName, options) {
+  try {
+    // this can throw if the package doesn't have an exported main field
+    return require.resolve(packageName, options);
+  } catch (ignore) {}
+
+  const paths = options?.paths ?? [process.cwd()];
+  for (const dir of paths) {
+    try {
+      const pathToCheck = path.resolve(dir, "node_modules", packageName);
+      if (fs.existsSync(pathToCheck)) {
+        return pathToCheck;
+      }
+    } catch (ignore) {
+      // ignore
+    }
+  }
+}
+
 function resolvePackageJSONPath(packageName, options) {
   try {
     return require.resolve(`${packageName}/package.json`, options);
   } catch (ignore) {}
 
   try {
     // try find last index of node_modules/<packageName>
-    const packageMainPath = require.resolve(packageName, options);
+    const packageMainPath = tryFindPackagePath(packageName, options);
+
+    if (!packageMainPath) {
+      // we couldn't find the main path, so we likely won't find the package.json either.
+      return undefined;
+    }
+
     const searchWord = `node_modules${path.sep}${packageName.replace(
       "/",
       path.sep
     )}`;
     const foundIndex = packageMainPath.lastIndexOf(searchWord);
 
     if (foundIndex > -1) {
-      const packagePath = packageMainPath.substr(
+      const packagePath = packageMainPath.slice(
         0,
         foundIndex + searchWord.length
       );
@@ -75,6 +100,7 @@ function resolvePackageJSONPath(packageName, options) {
     // this is a last-resort package.json path that we found near the resolved package,
     // but did not match the packageName or was in an invalid json file
     if (possiblePackageJSONPath) {
+      console.log("using possible package.json path", possiblePackageJSONPath)
       return possiblePackageJSONPath;
     }
   } catch (ignore) {}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@rigor789/resolve-package-path",
-  "version": "1.0.5",
+  "version": "1.0.6",
   "main": "index.js",
   "types": "index.d.ts",
   "files": [
@@ -14,8 +14,10 @@
   },
   "devDependencies": {
     "package-a": "./stubs/package-a",
+    "package-alias": "npm:@rigor789/resolve-package-path@latest",
     "package-b": "./stubs/package-b",
     "package-c": "./stubs/package-c",
+    "package-no-main-exports": "./stubs/package-no-main-exports",
     "@scope/package-a": "./stubs/@scope/package-a",
     "@scope/package-b": "./stubs/@scope/package-b",
     "@scope/package-c": "./stubs/@scope/package-c"

stubs/package-no-main-exports/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "package-no-main-exports",
+  "version": "1.0.0",
+  "type": "module",
+  "exports": {}
+}

test.js

@@ -2,7 +2,10 @@ const { resolvePackagePath } = require("./");
 
 const path = require("path");
 
-const expectedPath = (packageName) => {
+const expectedPath = (packageName, dir) => {
+  if (dir) {
+    return path.resolve(__dirname, dir, packageName);
+  }
   switch (process.env.PACKAGE_MANAGER) {
     case "yarn":
       return path.resolve(__dirname, "node_modules", packageName);
@@ -18,6 +21,10 @@ const tests = [
     packageName: "package-a",
     expectedPath: expectedPath("package-a"),
   },
+  {
+    packageName: "package-alias",
+    expectedPath: expectedPath("package-alias", "node_modules"),
+  },
   {
     packageName: "package-b",
     expectedPath: expectedPath("package-b"),
@@ -26,6 +33,10 @@ const tests = [
     packageName: "package-c",
     expectedPath: expectedPath("package-c"),
   },
+  {
+    packageName: "package-no-main-exports",
+    expectedPath: expectedPath("package-no-main-exports", "node_modules"),
+  },
   {
     packageName: "@scope/package-a",
     expectedPath: expectedPath("@scope/package-a"),
@@ -54,11 +65,13 @@ tests.map((test) => {
     console.log("OK");
   } else {
     console.error("FAIL");
-    console.error(`\nExpected \n\t"${packagePath}" \nto equal \n\t"${test.expectedPath}"`);
+    console.error(
+      `\nExpected \n\t"${packagePath}" \nto equal \n\t"${test.expectedPath}"`
+    );
 
     // set process to a failed exit code
     process.exitCode = 1;
   }
 
-  console.log('\n')
+  console.log("\n");
 });