Added new diagnostic rule reportPossiblyUnboundVariable, which is split off from reportUnboundVariable. This addresses #6896. (#7071)

docs/configuration.md

@@ -132,6 +132,8 @@ The following settings control pyright’s diagnostic output (warnings or errors
 
 <a name="reportOverlappingOverload"></a> **reportOverlappingOverload** [boolean or string, optional]: Generate or suppress diagnostics for function overloads that overlap in signature and obscure each other or have incompatible return types. The default value for this setting is `"error"`.
 
+<a name="reportPossiblyUnboundVariable"></a> **reportPossiblyUnboundVariable** [boolean or string, optional]: Generate or suppress diagnostics for variables that are possibly unbound on some code paths. The default value for this setting is `"error"`. The default value for this setting is `"error"`.
+
 <a name="reportMissingSuperCall"></a> **reportMissingSuperCall** [boolean or string, optional]: Generate or suppress diagnostics for `__init__`, `__init_subclass__`, `__enter__` and `__exit__` methods in a subclass that fail to call through to the same-named method on a base class. The default value for this setting is `"none"`.
 
 <a name="reportUninitializedInstanceVariable"></a> **reportUninitializedInstanceVariable** [boolean or string, optional]: Generate or suppress diagnostics for instance variables within a class that are not initialized or declared within the class body or the `__init__` method. The default value for this setting is `"none"`.
@@ -172,7 +174,7 @@ The following settings control pyright’s diagnostic output (warnings or errors
 
 <a name="reportUndefinedVariable"></a> **reportUndefinedVariable** [boolean or string, optional]: Generate or suppress diagnostics for undefined variables. The default value for this setting is `"error"`.
 
-<a name="reportUnboundVariable"></a> **reportUnboundVariable** [boolean or string, optional]: Generate or suppress diagnostics for unbound and possibly unbound variables. The default value for this setting is `"error"`.
+<a name="reportUnboundVariable"></a> **reportUnboundVariable** [boolean or string, optional]: Generate or suppress diagnostics for unbound variables. The default value for this setting is `"error"`.
 
 <a name="reportInvalidStubStatement"></a> **reportInvalidStubStatement** [boolean or string, optional]: Generate or suppress diagnostics for statements that are syntactically correct but have no purpose within a type stub file. The default value for this setting is `"none"`.
 
@@ -344,6 +346,7 @@ The following table lists the default severity levels for each diagnostic rule w
 | reportIncompatibleMethodOverride          | "none"     | "none"     | "error"    | "error"    |
 | reportIncompatibleVariableOverride        | "none"     | "none"     | "error"    | "error"    |
 | reportOverlappingOverload                 | "none"     | "none"     | "error"    | "error"    |
+| reportPossiblyUnboundVariable             | "none"     | "none"     | "error"    | "error"    |
 | reportConstantRedefinition                | "none"     | "none"     | "none"     | "error"    |
 | reportDeprecated                          | "none"     | "none"     | "none"     | "error"    |
 | reportDuplicateImport                     | "none"     | "none"     | "none"     | "error"    |

packages/pyright-internal/src/analyzer/checker.ts

@@ -4266,7 +4266,7 @@ export class Checker extends ParseTreeWalker {
                     );
                 } else if (isPossiblyUnbound(type)) {
                     this._evaluator.addDiagnostic(
-                        DiagnosticRule.reportUnboundVariable,
+                        DiagnosticRule.reportPossiblyUnboundVariable,
                         LocMessage.symbolIsPossiblyUnbound().format({ name: node.value }),
                         node
                     );

packages/pyright-internal/src/common/configOptions.ts

@@ -227,6 +227,9 @@ export interface DiagnosticRuleSet {
     // incompatible return types.
     reportOverlappingOverload: DiagnosticLevel;
 
+    // Report usage of possibly unbound variables.
+    reportPossiblyUnboundVariable: DiagnosticLevel;
+
     // Report failure to call super().__init__() in __init__ method.
     reportMissingSuperCall: DiagnosticLevel;
 
@@ -291,7 +294,7 @@ export interface DiagnosticRuleSet {
     // Report usage of undefined variables.
     reportUndefinedVariable: DiagnosticLevel;
 
-    // Report usage of unbound or possibly unbound variables.
+    // Report usage of unbound variables.
     reportUnboundVariable: DiagnosticLevel;
 
     // Report statements that are syntactically correct but
@@ -402,6 +405,7 @@ export function getDiagLevelDiagnosticRules() {
         DiagnosticRule.reportIncompatibleVariableOverride,
         DiagnosticRule.reportInconsistentConstructor,
         DiagnosticRule.reportOverlappingOverload,
+        DiagnosticRule.reportPossiblyUnboundVariable,
         DiagnosticRule.reportMissingSuperCall,
         DiagnosticRule.reportUninitializedInstanceVariable,
         DiagnosticRule.reportInvalidStringEscapeSequence,
@@ -494,6 +498,7 @@ export function getOffDiagnosticRuleSet(): DiagnosticRuleSet {
         reportIncompatibleVariableOverride: 'none',
         reportInconsistentConstructor: 'none',
         reportOverlappingOverload: 'none',
+        reportPossiblyUnboundVariable: 'none',
         reportMissingSuperCall: 'none',
         reportUninitializedInstanceVariable: 'none',
         reportInvalidStringEscapeSequence: 'none',
@@ -582,6 +587,7 @@ export function getBasicDiagnosticRuleSet(): DiagnosticRuleSet {
         reportIncompatibleVariableOverride: 'none',
         reportInconsistentConstructor: 'none',
         reportOverlappingOverload: 'none',
+        reportPossiblyUnboundVariable: 'none',
         reportMissingSuperCall: 'none',
         reportUninitializedInstanceVariable: 'none',
         reportInvalidStringEscapeSequence: 'warning',
@@ -670,6 +676,7 @@ export function getStandardDiagnosticRuleSet(): DiagnosticRuleSet {
         reportIncompatibleVariableOverride: 'error',
         reportInconsistentConstructor: 'none',
         reportOverlappingOverload: 'error',
+        reportPossiblyUnboundVariable: 'error',
         reportMissingSuperCall: 'none',
         reportUninitializedInstanceVariable: 'none',
         reportInvalidStringEscapeSequence: 'warning',
@@ -758,6 +765,7 @@ export function getStrictDiagnosticRuleSet(): DiagnosticRuleSet {
         reportIncompatibleVariableOverride: 'error',
         reportInconsistentConstructor: 'error',
         reportOverlappingOverload: 'error',
+        reportPossiblyUnboundVariable: 'error',
         reportMissingSuperCall: 'none',
         reportUninitializedInstanceVariable: 'none',
         reportInvalidStringEscapeSequence: 'error',

packages/pyright-internal/src/common/diagnosticRules.ts

@@ -56,6 +56,7 @@ export enum DiagnosticRule {
     reportIncompatibleVariableOverride = 'reportIncompatibleVariableOverride',
     reportInconsistentConstructor = 'reportInconsistentConstructor',
     reportOverlappingOverload = 'reportOverlappingOverload',
+    reportPossiblyUnboundVariable = 'reportPossiblyUnboundVariable',
     reportMissingSuperCall = 'reportMissingSuperCall',
     reportUninitializedInstanceVariable = 'reportUninitializedInstanceVariable',
     reportInvalidStringEscapeSequence = 'reportInvalidStringEscapeSequence',

packages/vscode-pyright/package.json

@@ -751,6 +751,22 @@
                                 false
                             ]
                         },
+                        "reportPossiblyUnboundVariable": {
+                            "type": [
+                                "string",
+                                "boolean"
+                            ],
+                            "description": "Diagnostics for the use of variables that may be unbound on some code paths.",
+                            "default": "error",
+                            "enum": [
+                                "none",
+                                "information",
+                                "warning",
+                                "error",
+                                true,
+                                false
+                            ]
+                        },
                         "reportMissingSuperCall": {
                             "type": [
                                 "string",
@@ -1108,7 +1124,7 @@
                                 "string",
                                 "boolean"
                             ],
-                            "description": "Diagnostics for unbound and possibly unbound variables.",
+                            "description": "Diagnostics for the use of unbound variables.",
                             "default": "error",
                             "enum": [
                                 "none",

packages/vscode-pyright/schemas/pyrightconfig.schema.json

@@ -377,6 +377,12 @@
       "title": "Controls reporting of function overloads that overlap in signature and obscure each other or do not agree on return type",
       "default": "error"
     },
+    "reportPossiblyUnboundVariable": {
+      "$id": "#/properties/reportPossiblyUnboundVariable",
+      "$ref": "#/definitions/diagnostic",
+      "title": "Controls reporting of attempts to use variable that is possibly unbound on some code paths",
+      "default": "error"
+    },
     "reportMissingSuperCall": {
       "$id": "#/properties/reportMissingSuperCall",
       "$ref": "#/definitions/diagnostic",
@@ -494,7 +500,7 @@
     "reportUnboundVariable": {
       "$id": "#/properties/reportUnboundVariable",
       "$ref": "#/definitions/diagnostic",
-      "title": "Controls reporting of attempts to use an unbound or possibly unbound variable",
+      "title": "Controls reporting of attempts to use an unbound variable",
       "default": "error"
     },
     "reportUndefinedVariable": {