Exclude comparable relation from literal type relation optimization

src/compiler/checker.ts

@@ -20882,14 +20882,15 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 if (containsType(targetTypes, source)) {
                     return Ternary.True;
                 }
-                if (getObjectFlags(target) & ObjectFlags.PrimitiveUnion && !(source.flags & TypeFlags.EnumLiteral) && (
+                if (relation !== comparableRelation && getObjectFlags(target) & ObjectFlags.PrimitiveUnion && !(source.flags & TypeFlags.EnumLiteral) && (
                     source.flags & (TypeFlags.StringLiteral | TypeFlags.BooleanLiteral | TypeFlags.BigIntLiteral) ||
                     (relation === subtypeRelation || relation === strictSubtypeRelation) && source.flags & TypeFlags.NumberLiteral)) {
                     // When relating a literal type to a union of primitive types, we know the relation is false unless
                     // the union contains the base primitive type or the literal type in one of its fresh/regular forms.
                     // We exclude numeric literals for non-subtype relations because numeric literals are assignable to
                     // numeric enum literals with the same value. Similarly, we exclude enum literal types because
-                    // identically named enum types are related (see isEmumTypeRelatedTo).
+                    // identically named enum types are related (see isEnumTypeRelatedTo). We exclude the comparable
+                    // relation in entirety because it needs to be checked in both directions.
                     const alternateForm = source === (source as StringLiteralType).regularType ? (source as StringLiteralType).freshType : (source as StringLiteralType).regularType;
                     const primitive = source.flags & TypeFlags.StringLiteral ? stringType :
                         source.flags & TypeFlags.NumberLiteral ? numberType :

tests/baselines/reference/comparableRelationBidirectional.symbols

@@ -0,0 +1,75 @@
+=== tests/cases/compiler/comparableRelationBidirectional.ts ===
+enum AutomationMode {
+>AutomationMode : Symbol(AutomationMode, Decl(comparableRelationBidirectional.ts, 0, 0))
+
+    NONE = "",
+>NONE : Symbol(AutomationMode.NONE, Decl(comparableRelationBidirectional.ts, 0, 21))
+
+    TIME = "time",
+>TIME : Symbol(AutomationMode.TIME, Decl(comparableRelationBidirectional.ts, 1, 14))
+
+    SYSTEM = "system",
+>SYSTEM : Symbol(AutomationMode.SYSTEM, Decl(comparableRelationBidirectional.ts, 2, 18))
+
+    LOCATION = "location",
+>LOCATION : Symbol(AutomationMode.LOCATION, Decl(comparableRelationBidirectional.ts, 3, 22))
+}
+
+interface ThemePreset {
+>ThemePreset : Symbol(ThemePreset, Decl(comparableRelationBidirectional.ts, 5, 1))
+
+    id: string;
+>id : Symbol(ThemePreset.id, Decl(comparableRelationBidirectional.ts, 7, 23))
+}
+
+interface Automation {
+>Automation : Symbol(Automation, Decl(comparableRelationBidirectional.ts, 9, 1))
+
+    mode: AutomationMode;
+>mode : Symbol(Automation.mode, Decl(comparableRelationBidirectional.ts, 11, 22))
+>AutomationMode : Symbol(AutomationMode, Decl(comparableRelationBidirectional.ts, 0, 0))
+}
+
+interface UserSettings {
+>UserSettings : Symbol(UserSettings, Decl(comparableRelationBidirectional.ts, 13, 1))
+
+    presets: ThemePreset[];
+>presets : Symbol(UserSettings.presets, Decl(comparableRelationBidirectional.ts, 15, 24))
+>ThemePreset : Symbol(ThemePreset, Decl(comparableRelationBidirectional.ts, 5, 1))
+
+    automation: Automation;
+>automation : Symbol(UserSettings.automation, Decl(comparableRelationBidirectional.ts, 16, 27))
+>Automation : Symbol(Automation, Decl(comparableRelationBidirectional.ts, 9, 1))
+}
+
+interface ExtensionData {
+>ExtensionData : Symbol(ExtensionData, Decl(comparableRelationBidirectional.ts, 18, 1))
+
+    settings: UserSettings;
+>settings : Symbol(ExtensionData.settings, Decl(comparableRelationBidirectional.ts, 20, 25))
+>UserSettings : Symbol(UserSettings, Decl(comparableRelationBidirectional.ts, 13, 1))
+}
+
+export function getMockData(): ExtensionData {
+>getMockData : Symbol(getMockData, Decl(comparableRelationBidirectional.ts, 22, 1))
+>ExtensionData : Symbol(ExtensionData, Decl(comparableRelationBidirectional.ts, 18, 1))
+
+    return {
+        settings: {
+>settings : Symbol(settings, Decl(comparableRelationBidirectional.ts, 25, 12))
+
+            presets: [],
+>presets : Symbol(presets, Decl(comparableRelationBidirectional.ts, 26, 19))
+
+            automation: {
+>automation : Symbol(automation, Decl(comparableRelationBidirectional.ts, 27, 24))
+
+                mode: "",
+>mode : Symbol(mode, Decl(comparableRelationBidirectional.ts, 28, 25))
+
+            },
+        } as UserSettings,
+>UserSettings : Symbol(UserSettings, Decl(comparableRelationBidirectional.ts, 13, 1))
+    }
+}
+

tests/baselines/reference/comparableRelationBidirectional.types

@@ -0,0 +1,72 @@
+=== tests/cases/compiler/comparableRelationBidirectional.ts ===
+enum AutomationMode {
+>AutomationMode : AutomationMode
+
+    NONE = "",
+>NONE : AutomationMode.NONE
+>"" : ""
+
+    TIME = "time",
+>TIME : AutomationMode.TIME
+>"time" : "time"
+
+    SYSTEM = "system",
+>SYSTEM : AutomationMode.SYSTEM
+>"system" : "system"
+
+    LOCATION = "location",
+>LOCATION : AutomationMode.LOCATION
+>"location" : "location"
+}
+
+interface ThemePreset {
+    id: string;
+>id : string
+}
+
+interface Automation {
+    mode: AutomationMode;
+>mode : AutomationMode
+}
+
+interface UserSettings {
+    presets: ThemePreset[];
+>presets : ThemePreset[]
+
+    automation: Automation;
+>automation : Automation
+}
+
+interface ExtensionData {
+    settings: UserSettings;
+>settings : UserSettings
+}
+
+export function getMockData(): ExtensionData {
+>getMockData : () => ExtensionData
+
+    return {
+>{        settings: {            presets: [],            automation: {                mode: "",            },        } as UserSettings,    } : { settings: UserSettings; }
+
+        settings: {
+>settings : UserSettings
+>{            presets: [],            automation: {                mode: "",            },        } as UserSettings : UserSettings
+>{            presets: [],            automation: {                mode: "",            },        } : { presets: never[]; automation: { mode: ""; }; }
+
+            presets: [],
+>presets : never[]
+>[] : never[]
+
+            automation: {
+>automation : { mode: ""; }
+>{                mode: "",            } : { mode: ""; }
+
+                mode: "",
+>mode : ""
+>"" : ""
+
+            },
+        } as UserSettings,
+    }
+}
+

tests/cases/compiler/comparableRelationBidirectional.ts

@@ -0,0 +1,37 @@
+// @strict: true
+// @noEmit: true
+
+enum AutomationMode {
+    NONE = "",
+    TIME = "time",
+    SYSTEM = "system",
+    LOCATION = "location",
+}
+
+interface ThemePreset {
+    id: string;
+}
+
+interface Automation {
+    mode: AutomationMode;
+}
+
+interface UserSettings {
+    presets: ThemePreset[];
+    automation: Automation;
+}
+
+interface ExtensionData {
+    settings: UserSettings;
+}
+
+export function getMockData(): ExtensionData {
+    return {
+        settings: {
+            presets: [],
+            automation: {
+                mode: "",
+            },
+        } as UserSettings,
+    }
+}