JS: Move package main-guessing into PackageJsonEx.qll

Author: asgerf

javascript/ql/lib/semmle/javascript/internal/paths/PackageJsonEx.qll

@@ -52,6 +52,17 @@ class PackageJsonEx extends PackageJson {
     )
   }
 
+  File getMainFileOrBestGuess() {
+    result = this.getMainFile()
+    or
+    not exists(this.getMainFile()) and
+    (
+      result = guessPackageJsonMain1(this)
+      or
+      result = guessPackageJsonMain2(this)
+    )
+  }
+
   string getAPathInFilesArray() {
     result = this.getPropValue("files").(JsonArray).getElementStringValue(_)
   }
@@ -83,3 +94,35 @@ private module ResolverConfig implements Folder::ResolveSig {
 }
 
 private module Resolver = Folder::Resolve<ResolverConfig>;
+
+/**
+ * Removes the scope from a package name, e.g. `@foo/bar` -> `bar`.
+ */
+bindingset[name]
+private string stripPackageScope(string name) { result = name.regexpReplaceAll("^@[^/]+/", "") }
+
+private File guessPackageJsonMain1(PackageJsonEx pkg) {
+  not exists(pkg.getMainFile()) and
+  exists(Folder folder, Folder subfolder |
+    folder = pkg.getFolder() and
+    (
+      subfolder = folder or
+      subfolder = folder.getChildContainer(getASrcFolderName()) or
+      subfolder =
+        folder
+            .getChildContainer(getASrcFolderName())
+            .(Folder)
+            .getChildContainer(getASrcFolderName())
+    )
+  |
+    result = subfolder.getJavaScriptFileOrTypings("index")
+    or
+    result = subfolder.getJavaScriptFileOrTypings(stripPackageScope(pkg.getDeclaredPackageName()))
+  )
+}
+
+private File guessPackageJsonMain2(PackageJsonEx pkg) {
+  not exists(pkg.getMainFile()) and
+  not exists(guessPackageJsonMain1(pkg)) and
+  result = pkg.getAFileInFilesArray()
+}

javascript/ql/lib/semmle/javascript/internal/paths/PathExprResolver.qll

@@ -164,49 +164,14 @@ private Container resolvePathExpr1(RelevantPathExpr expr) {
   )
 }
 
-/**
- * Removes the scope from a package name, e.g. `@foo/bar` -> `bar`.
- */
-bindingset[name]
-private string stripPackageScope(string name) { result = name.regexpReplaceAll("^@[^/]+/", "") }
-
-private File guessPackageJsonMain1(PackageJsonEx pkg) {
-  not exists(pkg.getMainFile()) and
-  exists(Folder folder, Folder subfolder |
-    folder = pkg.getFolder() and
-    (
-      subfolder = folder or
-      subfolder = folder.getChildContainer(getASrcFolderName()) or
-      subfolder =
-        folder
-            .getChildContainer(getASrcFolderName())
-            .(Folder)
-            .getChildContainer(getASrcFolderName())
-    )
-  |
-    result = subfolder.getJavaScriptFileOrTypings("index")
-    or
-    result = subfolder.getJavaScriptFileOrTypings(stripPackageScope(pkg.getDeclaredPackageName()))
-  )
-}
-
-private File guessPackageJsonMain2(PackageJsonEx pkg) {
-  not exists(pkg.getMainFile()) and
-  not exists(guessPackageJsonMain1(pkg)) and
-  result = pkg.getAFileInFilesArray()
-}
-
-private File getFileFromFolderImport(Folder folder) {
+File getFileFromFolderImport(Folder folder) {
   result = folder.getJavaScriptFileOrTypings("index")
   or
   // Note that unlike "exports" paths, "main" and "module" also take effect when the package
   // is imported via a relative path, e.g. `require("..")` targeting a folder with a package.json file.
-  exists(PackageJsonEx pkg | pkg.getFolder() = folder |
-    result = pkg.getMainFile()
-    or
-    result = guessPackageJsonMain1(pkg)
-    or
-    result = guessPackageJsonMain2(pkg)
+  exists(PackageJsonEx pkg |
+    pkg.getFolder() = folder and
+    result = pkg.getMainFileOrBestGuess()
   )
 }