Add fastpath to isRelatedTo for type references

src/compiler/checker.ts

@@ -15541,11 +15541,21 @@ namespace ts {
              * * Ternary.False if they are not related.
              */
             function isRelatedTo(originalSource: Type, originalTarget: Type, reportErrors = false, headMessage?: DiagnosticMessage, intersectionState = IntersectionState.None): Ternary {
+                // Before normalization: if `source` is type an object type, and `target` is primitive,
+                // skip all the checks we don't need and just return `isSimpleTypeRelatedTo` result
+                if (originalSource.flags & TypeFlags.Object && originalTarget.flags & TypeFlags.Primitive) {
+                    if (isSimpleTypeRelatedTo(originalSource, originalTarget, relation, reportErrors ? reportError : undefined)) {
+                        return Ternary.True;
+                    }
+                    reportErrorResults(originalSource, originalTarget, Ternary.False, !!(getObjectFlags(originalSource) & ObjectFlags.JsxAttributes));
+                    return Ternary.False;
+                }
+
                 // Normalize the source and target types: Turn fresh literal types into regular literal types,
                 // turn deferred type references into regular type references, simplify indexed access and
                 // conditional types, and resolve substitution types to either the substitution (on the source
                 // side) or the type variable (on the target side).
-                let source = getNormalizedType(originalSource, /*writing*/ false);
+                const source = getNormalizedType(originalSource, /*writing*/ false);
                 let target = getNormalizedType(originalTarget, /*writing*/ true);
 
                 if (source === target) return Ternary.True;
@@ -15679,6 +15689,7 @@ namespace ts {
                         }
                     }
                 }
+
                 // For certain combinations involving intersections and optional, excess, or mismatched properties we need
                 // an extra property check where the intersection is viewed as a single object. The following are motivating
                 // examples that all should be errors, but aren't without this extra property check:
@@ -15702,47 +15713,51 @@ namespace ts {
                     inPropertyCheck = false;
                 }
 
-                if (!result && reportErrors) {
-                    source = originalSource.aliasSymbol ? originalSource : source;
-                    target = originalTarget.aliasSymbol ? originalTarget : target;
-                    let maybeSuppress = overrideNextErrorInfo > 0;
-                    if (maybeSuppress) {
-                        overrideNextErrorInfo--;
-                    }
-                    if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Object) {
-                        const currentError = errorInfo;
-                        tryElaborateArrayLikeErrors(source, target, reportErrors);
-                        if (errorInfo !== currentError) {
-                            maybeSuppress = !!errorInfo;
+                reportErrorResults(source, target, result, isComparingJsxAttributes);
+                return result;
+
+                function reportErrorResults(source: Type, target: Type, result: Ternary, isComparingJsxAttributes: boolean) {
+                    if (!result && reportErrors) {
+                        source = originalSource.aliasSymbol ? originalSource : source;
+                        target = originalTarget.aliasSymbol ? originalTarget : target;
+                        let maybeSuppress = overrideNextErrorInfo > 0;
+                        if (maybeSuppress) {
+                            overrideNextErrorInfo--;
+                        }
+                        if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Object) {
+                            const currentError = errorInfo;
+                            tryElaborateArrayLikeErrors(source, target, reportErrors);
+                            if (errorInfo !== currentError) {
+                                maybeSuppress = !!errorInfo;
+                            }
                         }
-                    }
-                    if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Primitive) {
-                        tryElaborateErrorsForPrimitivesAndObjects(source, target);
-                    }
-                    else if (source.symbol && source.flags & TypeFlags.Object && globalObjectType === source) {
-                        reportError(Diagnostics.The_Object_type_is_assignable_to_very_few_other_types_Did_you_mean_to_use_the_any_type_instead);
-                    }
-                    else if (isComparingJsxAttributes && target.flags & TypeFlags.Intersection) {
-                        const targetTypes = (target as IntersectionType).types;
-                        const intrinsicAttributes = getJsxType(JsxNames.IntrinsicAttributes, errorNode);
-                        const intrinsicClassAttributes = getJsxType(JsxNames.IntrinsicClassAttributes, errorNode);
-                        if (intrinsicAttributes !== errorType && intrinsicClassAttributes !== errorType &&
-                            (contains(targetTypes, intrinsicAttributes) || contains(targetTypes, intrinsicClassAttributes))) {
-                            // do not report top error
+                        if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Primitive) {
+                            tryElaborateErrorsForPrimitivesAndObjects(source, target);
+                        }
+                        else if (source.symbol && source.flags & TypeFlags.Object && globalObjectType === source) {
+                            reportError(Diagnostics.The_Object_type_is_assignable_to_very_few_other_types_Did_you_mean_to_use_the_any_type_instead);
+                        }
+                        else if (isComparingJsxAttributes && target.flags & TypeFlags.Intersection) {
+                            const targetTypes = (target as IntersectionType).types;
+                            const intrinsicAttributes = getJsxType(JsxNames.IntrinsicAttributes, errorNode);
+                            const intrinsicClassAttributes = getJsxType(JsxNames.IntrinsicClassAttributes, errorNode);
+                            if (intrinsicAttributes !== errorType && intrinsicClassAttributes !== errorType &&
+                                (contains(targetTypes, intrinsicAttributes) || contains(targetTypes, intrinsicClassAttributes))) {
+                                // do not report top error
+                                return result;
+                            }
+                        }
+                        else {
+                            errorInfo = elaborateNeverIntersection(errorInfo, originalTarget);
+                        }
+                        if (!headMessage && maybeSuppress) {
+                            lastSkippedInfo = [source, target];
+                            // Used by, eg, missing property checking to replace the top-level message with a more informative one
                             return result;
                         }
+                        reportRelationError(headMessage, source, target);
                     }
-                    else {
-                        errorInfo = elaborateNeverIntersection(errorInfo, originalTarget);
-                    }
-                    if (!headMessage && maybeSuppress) {
-                        lastSkippedInfo = [source, target];
-                        // Used by, eg, missing property checking to replace the top-level message with a more informative one
-                        return result;
-                    }
-                    reportRelationError(headMessage, source, target);
                 }
-                return result;
             }
 
             function isIdenticalTo(source: Type, target: Type): Ternary {

tests/baselines/reference/recursiveArrayNotCircular.js

@@ -0,0 +1,66 @@
+//// [recursiveArrayNotCircular.ts]
+type Action<T, P> = P extends void ? { type : T } : { type: T, payload: P }
+
+enum ActionType {
+    Foo,
+    Bar,
+    Baz,
+    Batch
+}
+
+type ReducerAction =
+  | Action<ActionType.Bar, number>
+  | Action<ActionType.Baz, boolean>
+  | Action<ActionType.Foo, string>
+  | Action<ActionType.Batch, ReducerAction[]>
+
+function assertNever(a: never): never {
+    throw new Error("Unreachable!");
+}
+
+function reducer(action: ReducerAction): void {
+    switch(action.type) {
+        case ActionType.Bar:
+            const x: number = action.payload;
+            break;
+        case ActionType.Baz:
+            const y: boolean = action.payload;
+            break;
+        case ActionType.Foo:
+            const z: string = action.payload;
+            break;
+        case ActionType.Batch:
+            action.payload.map(reducer);
+            break;
+        default: return assertNever(action);
+    }
+}
+
+//// [recursiveArrayNotCircular.js]
+var ActionType;
+(function (ActionType) {
+    ActionType[ActionType["Foo"] = 0] = "Foo";
+    ActionType[ActionType["Bar"] = 1] = "Bar";
+    ActionType[ActionType["Baz"] = 2] = "Baz";
+    ActionType[ActionType["Batch"] = 3] = "Batch";
+})(ActionType || (ActionType = {}));
+function assertNever(a) {
+    throw new Error("Unreachable!");
+}
+function reducer(action) {
+    switch (action.type) {
+        case ActionType.Bar:
+            var x = action.payload;
+            break;
+        case ActionType.Baz:
+            var y = action.payload;
+            break;
+        case ActionType.Foo:
+            var z = action.payload;
+            break;
+        case ActionType.Batch:
+            action.payload.map(reducer);
+            break;
+        default: return assertNever(action);
+    }
+}

tests/baselines/reference/recursiveArrayNotCircular.symbols

@@ -0,0 +1,126 @@
+=== tests/cases/compiler/recursiveArrayNotCircular.ts ===
+type Action<T, P> = P extends void ? { type : T } : { type: T, payload: P }
+>Action : Symbol(Action, Decl(recursiveArrayNotCircular.ts, 0, 0))
+>T : Symbol(T, Decl(recursiveArrayNotCircular.ts, 0, 12))
+>P : Symbol(P, Decl(recursiveArrayNotCircular.ts, 0, 14))
+>P : Symbol(P, Decl(recursiveArrayNotCircular.ts, 0, 14))
+>type : Symbol(type, Decl(recursiveArrayNotCircular.ts, 0, 38))
+>T : Symbol(T, Decl(recursiveArrayNotCircular.ts, 0, 12))
+>type : Symbol(type, Decl(recursiveArrayNotCircular.ts, 0, 53))
+>T : Symbol(T, Decl(recursiveArrayNotCircular.ts, 0, 12))
+>payload : Symbol(payload, Decl(recursiveArrayNotCircular.ts, 0, 62))
+>P : Symbol(P, Decl(recursiveArrayNotCircular.ts, 0, 14))
+
+enum ActionType {
+>ActionType : Symbol(ActionType, Decl(recursiveArrayNotCircular.ts, 0, 75))
+
+    Foo,
+>Foo : Symbol(ActionType.Foo, Decl(recursiveArrayNotCircular.ts, 2, 17))
+
+    Bar,
+>Bar : Symbol(ActionType.Bar, Decl(recursiveArrayNotCircular.ts, 3, 8))
+
+    Baz,
+>Baz : Symbol(ActionType.Baz, Decl(recursiveArrayNotCircular.ts, 4, 8))
+
+    Batch
+>Batch : Symbol(ActionType.Batch, Decl(recursiveArrayNotCircular.ts, 5, 8))
+}
+
+type ReducerAction =
+>ReducerAction : Symbol(ReducerAction, Decl(recursiveArrayNotCircular.ts, 7, 1))
+
+  | Action<ActionType.Bar, number>
+>Action : Symbol(Action, Decl(recursiveArrayNotCircular.ts, 0, 0))
+>ActionType : Symbol(ActionType, Decl(recursiveArrayNotCircular.ts, 0, 75))
+>Bar : Symbol(ActionType.Bar, Decl(recursiveArrayNotCircular.ts, 3, 8))
+
+  | Action<ActionType.Baz, boolean>
+>Action : Symbol(Action, Decl(recursiveArrayNotCircular.ts, 0, 0))
+>ActionType : Symbol(ActionType, Decl(recursiveArrayNotCircular.ts, 0, 75))
+>Baz : Symbol(ActionType.Baz, Decl(recursiveArrayNotCircular.ts, 4, 8))
+
+  | Action<ActionType.Foo, string>
+>Action : Symbol(Action, Decl(recursiveArrayNotCircular.ts, 0, 0))
+>ActionType : Symbol(ActionType, Decl(recursiveArrayNotCircular.ts, 0, 75))
+>Foo : Symbol(ActionType.Foo, Decl(recursiveArrayNotCircular.ts, 2, 17))
+
+  | Action<ActionType.Batch, ReducerAction[]>
+>Action : Symbol(Action, Decl(recursiveArrayNotCircular.ts, 0, 0))
+>ActionType : Symbol(ActionType, Decl(recursiveArrayNotCircular.ts, 0, 75))
+>Batch : Symbol(ActionType.Batch, Decl(recursiveArrayNotCircular.ts, 5, 8))
+>ReducerAction : Symbol(ReducerAction, Decl(recursiveArrayNotCircular.ts, 7, 1))
+
+function assertNever(a: never): never {
+>assertNever : Symbol(assertNever, Decl(recursiveArrayNotCircular.ts, 13, 45))
+>a : Symbol(a, Decl(recursiveArrayNotCircular.ts, 15, 21))
+
+    throw new Error("Unreachable!");
+>Error : Symbol(Error, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+}
+
+function reducer(action: ReducerAction): void {
+>reducer : Symbol(reducer, Decl(recursiveArrayNotCircular.ts, 17, 1))
+>action : Symbol(action, Decl(recursiveArrayNotCircular.ts, 19, 17))
+>ReducerAction : Symbol(ReducerAction, Decl(recursiveArrayNotCircular.ts, 7, 1))
+
+    switch(action.type) {
+>action.type : Symbol(type, Decl(recursiveArrayNotCircular.ts, 0, 53), Decl(recursiveArrayNotCircular.ts, 0, 53), Decl(recursiveArrayNotCircular.ts, 0, 53), Decl(recursiveArrayNotCircular.ts, 0, 53), Decl(recursiveArrayNotCircular.ts, 0, 53))
+>action : Symbol(action, Decl(recursiveArrayNotCircular.ts, 19, 17))
+>type : Symbol(type, Decl(recursiveArrayNotCircular.ts, 0, 53), Decl(recursiveArrayNotCircular.ts, 0, 53), Decl(recursiveArrayNotCircular.ts, 0, 53), Decl(recursiveArrayNotCircular.ts, 0, 53), Decl(recursiveArrayNotCircular.ts, 0, 53))
+
+        case ActionType.Bar:
+>ActionType.Bar : Symbol(ActionType.Bar, Decl(recursiveArrayNotCircular.ts, 3, 8))
+>ActionType : Symbol(ActionType, Decl(recursiveArrayNotCircular.ts, 0, 75))
+>Bar : Symbol(ActionType.Bar, Decl(recursiveArrayNotCircular.ts, 3, 8))
+
+            const x: number = action.payload;
+>x : Symbol(x, Decl(recursiveArrayNotCircular.ts, 22, 17))
+>action.payload : Symbol(payload, Decl(recursiveArrayNotCircular.ts, 0, 62))
+>action : Symbol(action, Decl(recursiveArrayNotCircular.ts, 19, 17))
+>payload : Symbol(payload, Decl(recursiveArrayNotCircular.ts, 0, 62))
+
+            break;
+        case ActionType.Baz:
+>ActionType.Baz : Symbol(ActionType.Baz, Decl(recursiveArrayNotCircular.ts, 4, 8))
+>ActionType : Symbol(ActionType, Decl(recursiveArrayNotCircular.ts, 0, 75))
+>Baz : Symbol(ActionType.Baz, Decl(recursiveArrayNotCircular.ts, 4, 8))
+
+            const y: boolean = action.payload;
+>y : Symbol(y, Decl(recursiveArrayNotCircular.ts, 25, 17))
+>action.payload : Symbol(payload, Decl(recursiveArrayNotCircular.ts, 0, 62), Decl(recursiveArrayNotCircular.ts, 0, 62))
+>action : Symbol(action, Decl(recursiveArrayNotCircular.ts, 19, 17))
+>payload : Symbol(payload, Decl(recursiveArrayNotCircular.ts, 0, 62), Decl(recursiveArrayNotCircular.ts, 0, 62))
+
+            break;
+        case ActionType.Foo:
+>ActionType.Foo : Symbol(ActionType.Foo, Decl(recursiveArrayNotCircular.ts, 2, 17))
+>ActionType : Symbol(ActionType, Decl(recursiveArrayNotCircular.ts, 0, 75))
+>Foo : Symbol(ActionType.Foo, Decl(recursiveArrayNotCircular.ts, 2, 17))
+
+            const z: string = action.payload;
+>z : Symbol(z, Decl(recursiveArrayNotCircular.ts, 28, 17))
+>action.payload : Symbol(payload, Decl(recursiveArrayNotCircular.ts, 0, 62))
+>action : Symbol(action, Decl(recursiveArrayNotCircular.ts, 19, 17))
+>payload : Symbol(payload, Decl(recursiveArrayNotCircular.ts, 0, 62))
+
+            break;
+        case ActionType.Batch:
+>ActionType.Batch : Symbol(ActionType.Batch, Decl(recursiveArrayNotCircular.ts, 5, 8))
+>ActionType : Symbol(ActionType, Decl(recursiveArrayNotCircular.ts, 0, 75))
+>Batch : Symbol(ActionType.Batch, Decl(recursiveArrayNotCircular.ts, 5, 8))
+
+            action.payload.map(reducer);
+>action.payload.map : Symbol(Array.map, Decl(lib.es5.d.ts, --, --))
+>action.payload : Symbol(payload, Decl(recursiveArrayNotCircular.ts, 0, 62))
+>action : Symbol(action, Decl(recursiveArrayNotCircular.ts, 19, 17))
+>payload : Symbol(payload, Decl(recursiveArrayNotCircular.ts, 0, 62))
+>map : Symbol(Array.map, Decl(lib.es5.d.ts, --, --))
+>reducer : Symbol(reducer, Decl(recursiveArrayNotCircular.ts, 17, 1))
+
+            break;
+        default: return assertNever(action);
+>assertNever : Symbol(assertNever, Decl(recursiveArrayNotCircular.ts, 13, 45))
+>action : Symbol(action, Decl(recursiveArrayNotCircular.ts, 19, 17))
+    }
+}