Merge pull request #121 from bloomberg/isolated-declarations-unused-i…

…mports

Revert change in checker that prevented TS from removing  some imports

src/compiler/checker.ts

@@ -2764,10 +2764,6 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     return symbol;
                 }
                 if (symbol.flags & SymbolFlags.Alias) {
-                    // Do not take target symbol meaning into account in isolated declaration mode since we don't have access to info from other files.
-                    if (compilerOptions.isolatedDeclarations) {
-                        return symbol;
-                    }
                     const targetFlags = getSymbolFlags(symbol);
                     // `targetFlags` will be `SymbolFlags.All` if an error occurred in alias resolution; this avoids cascading errors
                     if (targetFlags & meaning) {

tests/baselines/reference/isolated-declarations/original/diff/decoratorMetadataWithImportDeclarationNameCollision7.d.ts.diff

@@ -0,0 +1,17 @@
+// [[Reason: TSC removes import that is not used in a semantically valid way. DTE can't know about this.]] ////
+
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision7.ts] ////
+
+===================================================================
+--- TSC	declarations
++++ DTE	declarations
+@@ -5,8 +5,9 @@
+     doSomething(): invalid;
+ }
+
+ //// [service.d.ts]
++import db from './db';
+ declare class MyClass {
+     db: db.db;
+     constructor(db: db.db);
+ }

tests/baselines/reference/isolated-declarations/original/diff/typeReferenceDirectives13.d.ts.diff

@@ -0,0 +1,16 @@
+// [[Reason: TSC removes type only import. DTE can't know import is type only.]] ////
+
+//// [tests/cases/compiler/typeReferenceDirectives13.ts] ////
+
+===================================================================
+--- TSC	declarations
++++ DTE	declarations
+@@ -1,7 +1,8 @@
+
+
+ //// [/app.d.ts]
++import { $ } from "./ref";
+ export interface A {
+     x: () => typeof $;
+ }
+

tests/baselines/reference/isolated-declarations/original/diff/typeReferenceDirectives5.d.ts.diff

@@ -0,0 +1,16 @@
+// [[Reason: TSC removes type only import. DTE can't know import is type only.]] ////
+
+//// [tests/cases/compiler/typeReferenceDirectives5.ts] ////
+
+===================================================================
+--- TSC	declarations
++++ DTE	declarations
+@@ -1,7 +1,8 @@
+
+
+ //// [/app.d.ts]
++import { $ } from "./ref";
+ export interface A {
+     x: typeof $;
+ }
+

tests/baselines/reference/isolated-declarations/original/dte/decoratorMetadataWithImportDeclarationNameCollision7.d.ts

@@ -0,0 +1,83 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision7.ts] ////
+
+//// [db.ts]
+export default class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import db from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db.db; //error
+
+    constructor(db: db.db) { // error
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+/// [Declarations] ////
+
+
+
+//// [db.d.ts]
+export default class db {
+    doSomething(): invalid;
+}
+
+//// [service.d.ts]
+import db from './db';
+declare class MyClass {
+    db: db.db;
+    constructor(db: db.db);
+}
+export { MyClass };
+
+/// [Errors] ////
+
+db.ts(2,12): error TS9007: Declaration emit for this file requires type resolution. An explicit type annotation may unblock declaration emit.
+service.ts(7,9): error TS2702: 'db' only refers to a type, but is being used as a namespace here.
+service.ts(7,9): error TS4031: Public property 'db' of exported class has or is using private name 'db'.
+service.ts(9,21): error TS2702: 'db' only refers to a type, but is being used as a namespace here.
+service.ts(9,21): error TS4063: Parameter 'db' of constructor from exported class has or is using private name 'db'.
+
+
+==== db.ts (1 errors) ====
+    export default class db {
+        public doSomething() {
+               ~~~~~~~~~~~
+!!! error TS9007: Declaration emit for this file requires type resolution. An explicit type annotation may unblock declaration emit.
+        }
+    }
+
+==== service.ts (4 errors) ====
+    import db from './db';
+    function someDecorator(target) {
+        return target;
+    }
+    @someDecorator
+    class MyClass {
+        db: db.db; //error
+            ~~
+!!! error TS2702: 'db' only refers to a type, but is being used as a namespace here.
+            ~~
+!!! error TS4031: Public property 'db' of exported class has or is using private name 'db'.
+
+        constructor(db: db.db) { // error
+                        ~~
+!!! error TS2702: 'db' only refers to a type, but is being used as a namespace here.
+                        ~~
+!!! error TS4063: Parameter 'db' of constructor from exported class has or is using private name 'db'.
+            this.db = db;
+            this.db.doSomething();
+        }
+    }
+    export {MyClass};
+

tests/baselines/reference/isolated-declarations/original/dte/typeReferenceDirectives13.d.ts

@@ -0,0 +1,46 @@
+//// [tests/cases/compiler/typeReferenceDirectives13.ts] ////
+
+//// [/app.ts]
+/// <reference types="lib"/>
+import {$} from "./ref";
+export interface A {
+    x: () => typeof $
+}
+
+//// [/ref.d.ts]
+export interface $ { x }
+
+//// [/types/lib/index.d.ts]
+declare let $: { x: number }
+
+
+/// [Declarations] ////
+
+
+
+//// [/app.d.ts]
+import { $ } from "./ref";
+export interface A {
+    x: () => typeof $;
+}
+
+/// [Errors] ////
+
+/app.ts(1,23): error TS9010: Reference directives are not supported in isolated declaration mode.
+
+
+==== /app.ts (1 errors) ====
+    /// <reference types="lib"/>
+                          ~~~
+!!! error TS9010: Reference directives are not supported in isolated declaration mode.
+    import {$} from "./ref";
+    export interface A {
+        x: () => typeof $
+    }
+
+==== /ref.d.ts (0 errors) ====
+    export interface $ { x }
+
+==== /types/lib/index.d.ts (0 errors) ====
+    declare let $: { x: number }
+

tests/baselines/reference/isolated-declarations/original/dte/typeReferenceDirectives5.d.ts

@@ -0,0 +1,44 @@
+//// [tests/cases/compiler/typeReferenceDirectives5.ts] ////
+
+//// [/app.ts]
+/// <reference types="lib"/>
+import {$} from "./ref";
+export interface A {
+    x: typeof $;
+}
+//// [/ref.d.ts]
+export interface $ { x }
+
+//// [/types/lib/index.d.ts]
+declare let $: { x: number }
+
+
+/// [Declarations] ////
+
+
+
+//// [/app.d.ts]
+import { $ } from "./ref";
+export interface A {
+    x: typeof $;
+}
+
+/// [Errors] ////
+
+/app.ts(1,23): error TS9010: Reference directives are not supported in isolated declaration mode.
+
+
+==== /app.ts (1 errors) ====
+    /// <reference types="lib"/>
+                          ~~~
+!!! error TS9010: Reference directives are not supported in isolated declaration mode.
+    import {$} from "./ref";
+    export interface A {
+        x: typeof $;
+    }
+==== /ref.d.ts (0 errors) ====
+    export interface $ { x }
+
+==== /types/lib/index.d.ts (0 errors) ====
+    declare let $: { x: number }
+

tests/baselines/reference/isolated-declarations/original/tsc/decoratorMetadataWithImportDeclarationNameCollision7.d.ts

@@ -0,0 +1,82 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision7.ts] ////
+
+//// [db.ts]
+export default class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import db from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db.db; //error
+
+    constructor(db: db.db) { // error
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+/// [Declarations] ////
+
+
+
+//// [db.d.ts]
+export default class db {
+    doSomething(): invalid;
+}
+
+//// [service.d.ts]
+declare class MyClass {
+    db: db.db;
+    constructor(db: db.db);
+}
+export { MyClass };
+
+/// [Errors] ////
+
+db.ts(2,12): error TS9007: Declaration emit for this file requires type resolution. An explicit type annotation may unblock declaration emit.
+service.ts(7,9): error TS2702: 'db' only refers to a type, but is being used as a namespace here.
+service.ts(7,9): error TS4031: Public property 'db' of exported class has or is using private name 'db'.
+service.ts(9,21): error TS2702: 'db' only refers to a type, but is being used as a namespace here.
+service.ts(9,21): error TS4063: Parameter 'db' of constructor from exported class has or is using private name 'db'.
+
+
+==== db.ts (1 errors) ====
+    export default class db {
+        public doSomething() {
+               ~~~~~~~~~~~
+!!! error TS9007: Declaration emit for this file requires type resolution. An explicit type annotation may unblock declaration emit.
+        }
+    }
+
+==== service.ts (4 errors) ====
+    import db from './db';
+    function someDecorator(target) {
+        return target;
+    }
+    @someDecorator
+    class MyClass {
+        db: db.db; //error
+            ~~
+!!! error TS2702: 'db' only refers to a type, but is being used as a namespace here.
+            ~~
+!!! error TS4031: Public property 'db' of exported class has or is using private name 'db'.
+
+        constructor(db: db.db) { // error
+                        ~~
+!!! error TS2702: 'db' only refers to a type, but is being used as a namespace here.
+                        ~~
+!!! error TS4063: Parameter 'db' of constructor from exported class has or is using private name 'db'.
+            this.db = db;
+            this.db.doSomething();
+        }
+    }
+    export {MyClass};
+

tests/baselines/reference/isolated-declarations/original/tsc/typeReferenceDirectives13.d.ts

@@ -0,0 +1,45 @@
+//// [tests/cases/compiler/typeReferenceDirectives13.ts] ////
+
+//// [/app.ts]
+/// <reference types="lib"/>
+import {$} from "./ref";
+export interface A {
+    x: () => typeof $
+}
+
+//// [/ref.d.ts]
+export interface $ { x }
+
+//// [/types/lib/index.d.ts]
+declare let $: { x: number }
+
+
+/// [Declarations] ////
+
+
+
+//// [/app.d.ts]
+export interface A {
+    x: () => typeof $;
+}
+
+/// [Errors] ////
+
+/app.ts(1,23): error TS9010: Reference directives are not supported in isolated declaration mode.
+
+
+==== /app.ts (1 errors) ====
+    /// <reference types="lib"/>
+                          ~~~
+!!! error TS9010: Reference directives are not supported in isolated declaration mode.
+    import {$} from "./ref";
+    export interface A {
+        x: () => typeof $
+    }
+
+==== /ref.d.ts (0 errors) ====
+    export interface $ { x }
+
+==== /types/lib/index.d.ts (0 errors) ====
+    declare let $: { x: number }
+