feat!: Resolve references to global var/function, add addGlobals() (#682)

* feat!: Close `var` and `function` references on global scope

* add `ScopeManager#addGlobals`

* refactor

* add more tests

* rename add-globals.js to add-globals.test.js

* update docs

Author: mdjermanovic

packages/eslint-scope/README.md

@@ -89,6 +89,11 @@ The `ScopeManager` class is at the core of eslint-scope and is returned when you
 
 #### Methods
 
+- **`addGlobals(names)`**
+  Adds variables to the global scope and resolves references to them.
+  - `names` - An array of strings, the names of variables to add to the global scope.
+  - Returns: `undefined`.
+
 - **`acquire(node, inner)`**
   Acquires the appropriate scope for a given node.
   - `node` - The AST node to acquire the scope from.

packages/eslint-scope/lib/scope-manager.js

@@ -182,6 +182,16 @@ class ScopeManager {
         return null;
     }
 
+    /**
+     * Add global variables and resolve their references.
+     * @function ScopeManager#addGlobals
+     * @param {string[]} names Names of global variables to add.
+     * @returns {void}
+     */
+    addGlobals(names) {
+        this.globalScope.__addVariables(names);
+    }
+
     attach() { } // eslint-disable-line class-methods-use-this -- Desired as instance method
 
     detach() { } // eslint-disable-line class-methods-use-this -- Desired as instance method

packages/eslint-scope/lib/scope.js

@@ -122,18 +122,6 @@ function registerScope(scopeManager, scope) {
     }
 }
 
-/**
- * Should be statically
- * @param {Object} def def
- * @returns {boolean} should be statically
- */
-function shouldBeStatically(def) {
-    return (
-        (def.type === Variable.ClassName) ||
-        (def.type === Variable.Variable && def.parent.kind !== "var")
-    );
-}
-
 /**
  * @constructor Scope
  */
@@ -267,22 +255,7 @@ class Scope {
     }
 
     __shouldStaticallyClose(scopeManager) {
-        return (!this.dynamic || scopeManager.__isOptimistic());
-    }
-
-    __shouldStaticallyCloseForGlobal(ref) {
-
-        // On global scope, let/const/class declarations should be resolved statically.
-        const name = ref.identifier.name;
-
-        if (!this.set.has(name)) {
-            return false;
-        }
-
-        const variable = this.set.get(name);
-        const defs = variable.defs;
-
-        return defs.length > 0 && defs.every(shouldBeStatically);
+        return (!this.dynamic || scopeManager.__isOptimistic() || this.type === "global");
     }
 
     __staticCloseRef(ref) {
@@ -302,26 +275,13 @@ class Scope {
         } while (current);
     }
 
-    __globalCloseRef(ref) {
-
-        // let/const/class declarations should be resolved statically.
-        // others should be resolved dynamically.
-        if (this.__shouldStaticallyCloseForGlobal(ref)) {
-            this.__staticCloseRef(ref);
-        } else {
-            this.__dynamicCloseRef(ref);
-        }
-    }
-
     __close(scopeManager) {
         let closeRef;
 
         if (this.__shouldStaticallyClose(scopeManager)) {
             closeRef = this.__staticCloseRef;
-        } else if (this.type !== "global") {
-            closeRef = this.__dynamicCloseRef;
         } else {
-            closeRef = this.__globalCloseRef;
+            closeRef = this.__dynamicCloseRef;
         }
 
         // Try Resolving all references in this scope.
@@ -560,9 +520,11 @@ class GlobalScope extends Scope {
 
         }
 
-        this.implicit.left = this.__left;
+        super.__close(scopeManager);
 
-        return super.__close(scopeManager);
+        this.implicit.left = [...this.through];
+
+        return null;
     }
 
     __defineImplicit(node, def) {
@@ -576,6 +538,51 @@ class GlobalScope extends Scope {
             );
         }
     }
+
+    __addVariables(names) {
+        for (const name of names) {
+            this.__defineGeneric(
+                name,
+                this.set,
+                this.variables,
+                null,
+                null
+            );
+        }
+
+        const namesSet = new Set(names);
+
+        this.through = this.through.filter(reference => {
+            const name = reference.identifier.name;
+
+            if (namesSet.has(name)) {
+                const variable = this.set.get(name);
+
+                reference.resolved = variable;
+                variable.references.push(reference);
+
+                return false;
+            }
+
+            return true;
+        });
+
+        this.implicit.variables = this.implicit.variables.filter(variable => {
+            const name = variable.name;
+
+            if (namesSet.has(name)) {
+                this.implicit.set.delete(name);
+
+                return false;
+            }
+
+            return true;
+        });
+
+        this.implicit.left = this.implicit.left.filter(
+            reference => !namesSet.has(reference.identifier.name)
+        );
+    }
 }
 
 /**