fix: Resolve the package of class/module symbols from the declaring file

typeToSymbol resolved the package of a class or module type with
getPackageInfo(node, ...), which classifies by the file containing the
reference. Every reference emitted while visiting a project file is in
the project, so any class reached through an alias declaration
(`pkg.Thing`, or `Thing` re-exported from a submodule) was emitted under
the project package instead of the package that declares it. Functions
already used guessPackage(decl.moduleName, decl.path) and were correct.

Use guessPackage with the type's own moduleName and filePath for classes,
modules and TypeVar bounds, falling back to a local symbol when the
package is unknown, as getFunctionSymbol does.

Adds a snapshot test with a fake `widgets` package exposed through
extraPaths and listed in testEnv.json, so references to classes
re-exported from a submodule are checked against the dependency's
package.

Author: anguslees

packages/pyright-scip/snapshots/input/external_class_import/external_class.py

@@ -0,0 +1,10 @@
+import widgets
+from widgets import Widget
+
+
+def render(name: str, width: int) -> str:
+    widget: widgets.Widget = widgets.Widget(name, width=width)
+    try:
+        return widgets.Widget.render(widget, prefix="> ")
+    except widgets.WidgetError:
+        return ""

packages/pyright-scip/snapshots/input/external_class_import/pyrightconfig.json

@@ -0,0 +1,4 @@
+{
+    "pythonVersion": "3.11",
+    "extraPaths": ["../../site-packages"]
+}

packages/pyright-scip/snapshots/output/external_class_import/external_class.py

@@ -0,0 +1,37 @@
+# < definition scip-python python snapshot-util 0.1 external_class/__init__:
+
+import widgets
+#      ^^^^^^^ reference  widgets 1.2.3 widgets/__init__:
+from widgets import Widget
+#    ^^^^^^^ reference  widgets 1.2.3 widgets/__init__:
+#                   ^^^^^^ reference  widgets 1.2.3 `widgets.models`/Widget#
+
+
+def render(name: str, width: int) -> str:
+#   ^^^^^^ definition  snapshot-util 0.1 external_class/render().
+#          ^^^^ definition  snapshot-util 0.1 external_class/render().(name)
+#                ^^^ reference  python-stdlib 3.11 builtins/str#
+#                     ^^^^^ definition  snapshot-util 0.1 external_class/render().(width)
+#                            ^^^ reference  python-stdlib 3.11 builtins/int#
+#                                    ^^^ reference  python-stdlib 3.11 builtins/str#
+    widget: widgets.Widget = widgets.Widget(name, width=width)
+#   ^^^^^^ definition local 0
+#           ^^^^^^^ reference  widgets 1.2.3 widgets/__init__:
+#                   ^^^^^^ reference  widgets 1.2.3 `widgets.models`/Widget#
+#                            ^^^^^^^ reference  widgets 1.2.3 widgets/__init__:
+#                                    ^^^^^^ reference  widgets 1.2.3 `widgets.models`/Widget#
+#                                           ^^^^ reference  snapshot-util 0.1 external_class/render().(name)
+#                                                 ^^^^^ reference  widgets 1.2.3 `widgets.models`/Widget#__init__().(width)
+#                                                       ^^^^^ reference  snapshot-util 0.1 external_class/render().(width)
+    try:
+        return widgets.Widget.render(widget, prefix="> ")
+#              ^^^^^^^ reference  widgets 1.2.3 widgets/__init__:
+#                      ^^^^^^ reference  widgets 1.2.3 `widgets.models`/Widget#
+#                             ^^^^^^ reference  widgets 1.2.3 `widgets.models`/Widget#render().
+#                                    ^^^^^^ reference local 0
+#                                            ^^^^^^ reference  widgets 1.2.3 `widgets.models`/Widget#render().(prefix)
+    except widgets.WidgetError:
+#          ^^^^^^^ reference  widgets 1.2.3 widgets/__init__:
+#                  ^^^^^^^^^^^ reference  widgets 1.2.3 `widgets.models`/WidgetError#
+        return ""
+

packages/pyright-scip/snapshots/site-packages/widgets/__init__.py

@@ -0,0 +1,3 @@
+from .models import Widget, WidgetError
+
+__all__ = ["Widget", "WidgetError"]

packages/pyright-scip/snapshots/site-packages/widgets/models.py

@@ -0,0 +1,11 @@
+class WidgetError(Exception):
+    pass
+
+
+class Widget:
+    def __init__(self, name: str, width: int = 0) -> None:
+        self.name = name
+        self.width = width
+
+    def render(self, prefix: str = "") -> str:
+        return prefix + self.name

packages/pyright-scip/snapshots/testEnv.json

@@ -13,5 +13,10 @@
         "name": "sqlparse",
         "version": "0.4.2",
         "files": []
+    },
+    {
+        "name": "widgets",
+        "version": "1.2.3",
+        "files": ["widgets/__init__.py", "widgets/models.py"]
     }
 ]

packages/pyright-scip/src/treeVisitor.ts

@@ -1123,7 +1123,13 @@ export class TreeVisitor extends ParseTreeWalker {
                                 const bound = typeVar.details.boundType! as ClassType;
 
                                 return this.getSymbolOnce(node, () => {
-                                    const pythonPackage = this.getPackageInfo(node, bound.details.moduleName)!;
+                                    const pythonPackage = this.guessPackage(
+                                        bound.details.moduleName,
+                                        bound.details.filePath
+                                    );
+                                    if (!pythonPackage) {
+                                        return ScipSymbol.local(this.counter.next());
+                                    }
                                     let symbol = Symbols.makeTerm(
                                         Symbols.makeType(
                                             Symbols.makeModule(pythonPackage, bound.details.moduleName),
@@ -1343,7 +1349,12 @@ export class TreeVisitor extends ParseTreeWalker {
             }
             return this.getFunctionSymbol(decl);
         } else if (Types.isClass(typeObj)) {
-            const pythonPackage = this.getPackageInfo(node, typeObj.details.moduleName)!;
+            // The package comes from the declaring file. `node` is the referencing
+            // site, which is in the project whenever a project file is visited.
+            const pythonPackage = this.guessPackage(typeObj.details.moduleName, typeObj.details.filePath);
+            if (!pythonPackage) {
+                return ScipSymbol.local(this.counter.next());
+            }
             return Symbols.makeClass(pythonPackage, typeObj.details.moduleName, node.value);
         } else if (Types.isClassInstance(typeObj)) {
             typeObj = typeObj as ClassType;
@@ -1352,7 +1363,10 @@ export class TreeVisitor extends ParseTreeWalker {
         } else if (Types.isTypeVar(typeObj)) {
             throw 'typevar';
         } else if (Types.isModule(typeObj)) {
-            const pythonPackage = this.getPackageInfo(node, typeObj.moduleName)!;
+            const pythonPackage = this.guessPackage(typeObj.moduleName, typeObj.filePath);
+            if (!pythonPackage) {
+                return ScipSymbol.local(this.counter.next());
+            }
             return Symbols.makeModuleInit(pythonPackage, typeObj.moduleName);
         } else if (Types.isOverloadedFunction(typeObj)) {
             if (!typeObj.overloads) {