add support for nonnull jsdoc

src/compiler/checker.ts

@@ -21712,7 +21712,8 @@ namespace ts {
                 case SyntaxKind.ParenthesizedExpression: {
                     // Like in `checkParenthesizedExpression`, an `/** @type {xyz} */` comment before a parenthesized expression acts as a type cast.
                     const tag = isInJSFile(parent) ? getJSDocTypeTag(parent) : undefined;
-                    return tag ? getTypeFromTypeNode(tag.typeExpression.type) : getContextualType(<ParenthesizedExpression>parent, contextFlags);
+                    const type = tag ? getTypeFromTypeNode(tag.typeExpression.type) : getContextualType(<ParenthesizedExpression>parent, contextFlags);
+                    return type && getJSDocNonNullTag(node) ? getNonNullableType(type) : type;
                 }
                 case SyntaxKind.JsxExpression:
                     return getContextualTypeForJsxExpression(<JsxExpression>parent);
@@ -27982,10 +27983,8 @@ namespace ts {
 
         function checkParenthesizedExpression(node: ParenthesizedExpression, checkMode?: CheckMode): Type {
             const tag = isInJSFile(node) ? getJSDocTypeTag(node) : undefined;
-            if (tag) {
-                return checkAssertionWorker(tag, tag.typeExpression.type, node.expression, checkMode);
-            }
-            return checkExpression(node.expression, checkMode);
+            const type = tag ? checkAssertionWorker(tag, tag.typeExpression.type, node.expression, checkMode) : checkExpression(node.expression, checkMode);
+            return getJSDocNonNullTag(node) ? getNonNullableType(type) : type;
         }
 
         function checkExpressionWorker(node: Expression | QualifiedName, checkMode: CheckMode | undefined, forceTuple?: boolean): Type {
@@ -32376,7 +32375,7 @@ namespace ts {
                 if (getModifierFlags(member) & ModifierFlags.Ambient) {
                     continue;
                 }
-                if (isInstancePropertyWithoutInitializer(member)) {
+                if (isInstancePropertyWithoutInitializer(member) && !isNonNullPropertyWithJSDoc(member)) {
                     const propName = (<PropertyDeclaration>member).name;
                     if (isIdentifier(propName) || isPrivateIdentifier(propName)) {
                         const type = getTypeOfSymbol(getSymbolOfNode(member));
@@ -32390,6 +32389,10 @@ namespace ts {
             }
         }
 
+        function isNonNullPropertyWithJSDoc (node: Node) {
+            return !!(isInJSFile(node) && getJSDocNonNullTag(node));
+        }
+
         function isInstancePropertyWithoutInitializer(node: Node) {
             return node.kind === SyntaxKind.PropertyDeclaration &&
                 !hasModifier(node, ModifierFlags.Static | ModifierFlags.Abstract) &&

src/compiler/parser.ts

@@ -516,6 +516,7 @@ namespace ts {
             case SyntaxKind.JSDocPrivateTag:
             case SyntaxKind.JSDocProtectedTag:
             case SyntaxKind.JSDocReadonlyTag:
+            case SyntaxKind.JSDocNonNullTag:
                 return visitNode(cbNode, (node as JSDocTag).tagName);
             case SyntaxKind.PartiallyEmittedExpression:
                 return visitNode(cbNode, (<PartiallyEmittedExpression>node).expression);
@@ -6942,6 +6943,9 @@ namespace ts {
                         case "readonly":
                             tag = parseSimpleTag(start, SyntaxKind.JSDocReadonlyTag, tagName);
                             break;
+                        case "nonnull":
+                            tag = parseSimpleTag(start, SyntaxKind.JSDocNonNullTag, tagName);
+                            break;
                         case "this":
                             tag = parseThisTag(start, tagName);
                             break;

src/compiler/types.ts

@@ -483,6 +483,7 @@ namespace ts {
         JSDocTemplateTag,
         JSDocTypedefTag,
         JSDocPropertyTag,
+        JSDocNonNullTag,
 
         // Synthesized list
         SyntaxList,
@@ -2637,6 +2638,10 @@ namespace ts {
         kind: SyntaxKind.JSDocTag;
     }
 
+    export interface JSDocNonNullTag extends JSDocTag {
+        kind: SyntaxKind.JSDocNonNullTag;
+    }
+
     /**
      * Note that `@extends` is a synonym of `@augments`.
      * Both tags are represented by this interface.

src/compiler/utilitiesPublic.ts

@@ -726,6 +726,10 @@ namespace ts {
         return undefined;
     }
 
+    export function getJSDocNonNullTag(node: Node): JSDocNonNullTag | undefined {
+        return getFirstJSDocTag(node, jsJSDocNonNullTag);
+    }
+
     /**
      * Gets the type node for the node if provided via JSDoc.
      *
@@ -1622,6 +1626,10 @@ namespace ts {
         return node.kind === SyntaxKind.JSDocTypeTag;
     }
 
+    export function jsJSDocNonNullTag(node: Node): node is JSDocNonNullTag {
+        return node.kind === SyntaxKind.JSDocNonNullTag;
+    }
+
     export function isJSDocTemplateTag(node: Node): node is JSDocTemplateTag {
         return node.kind === SyntaxKind.JSDocTemplateTag;
     }

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -398,14 +398,15 @@ declare namespace ts {
         JSDocTemplateTag = 320,
         JSDocTypedefTag = 321,
         JSDocPropertyTag = 322,
-        SyntaxList = 323,
-        NotEmittedStatement = 324,
-        PartiallyEmittedExpression = 325,
-        CommaListExpression = 326,
-        MergeDeclarationMarker = 327,
-        EndOfDeclarationMarker = 328,
-        SyntheticReferenceExpression = 329,
-        Count = 330,
+        JSDocNonNullTag = 323,
+        SyntaxList = 324,
+        NotEmittedStatement = 325,
+        PartiallyEmittedExpression = 326,
+        CommaListExpression = 327,
+        MergeDeclarationMarker = 328,
+        EndOfDeclarationMarker = 329,
+        SyntheticReferenceExpression = 330,
+        Count = 331,
         FirstAssignment = 62,
         LastAssignment = 74,
         FirstCompoundAssignment = 63,
@@ -1624,6 +1625,9 @@ declare namespace ts {
     export interface JSDocUnknownTag extends JSDocTag {
         kind: SyntaxKind.JSDocTag;
     }
+    export interface JSDocNonNullTag extends JSDocTag {
+        kind: SyntaxKind.JSDocNonNullTag;
+    }
     /**
      * Note that `@extends` is a synonym of `@augments`.
      * Both tags are represented by this interface.
@@ -3514,6 +3518,7 @@ declare namespace ts {
     function getJSDocTemplateTag(node: Node): JSDocTemplateTag | undefined;
     /** Gets the JSDoc type tag for the node if present and valid */
     function getJSDocTypeTag(node: Node): JSDocTypeTag | undefined;
+    function getJSDocNonNullTag(node: Node): JSDocNonNullTag | undefined;
     /**
      * Gets the type node for the node if provided via JSDoc.
      *
@@ -3721,6 +3726,7 @@ declare namespace ts {
     function isJSDocParameterTag(node: Node): node is JSDocParameterTag;
     function isJSDocReturnTag(node: Node): node is JSDocReturnTag;
     function isJSDocTypeTag(node: Node): node is JSDocTypeTag;
+    function jsJSDocNonNullTag(node: Node): node is JSDocNonNullTag;
     function isJSDocTemplateTag(node: Node): node is JSDocTemplateTag;
     function isJSDocTypedefTag(node: Node): node is JSDocTypedefTag;
     function isJSDocPropertyTag(node: Node): node is JSDocPropertyTag;

tests/baselines/reference/api/typescript.d.ts

@@ -398,14 +398,15 @@ declare namespace ts {
         JSDocTemplateTag = 320,
         JSDocTypedefTag = 321,
         JSDocPropertyTag = 322,
-        SyntaxList = 323,
-        NotEmittedStatement = 324,
-        PartiallyEmittedExpression = 325,
-        CommaListExpression = 326,
-        MergeDeclarationMarker = 327,
-        EndOfDeclarationMarker = 328,
-        SyntheticReferenceExpression = 329,
-        Count = 330,
+        JSDocNonNullTag = 323,
+        SyntaxList = 324,
+        NotEmittedStatement = 325,
+        PartiallyEmittedExpression = 326,
+        CommaListExpression = 327,
+        MergeDeclarationMarker = 328,
+        EndOfDeclarationMarker = 329,
+        SyntheticReferenceExpression = 330,
+        Count = 331,
         FirstAssignment = 62,
         LastAssignment = 74,
         FirstCompoundAssignment = 63,
@@ -1624,6 +1625,9 @@ declare namespace ts {
     export interface JSDocUnknownTag extends JSDocTag {
         kind: SyntaxKind.JSDocTag;
     }
+    export interface JSDocNonNullTag extends JSDocTag {
+        kind: SyntaxKind.JSDocNonNullTag;
+    }
     /**
      * Note that `@extends` is a synonym of `@augments`.
      * Both tags are represented by this interface.
@@ -3514,6 +3518,7 @@ declare namespace ts {
     function getJSDocTemplateTag(node: Node): JSDocTemplateTag | undefined;
     /** Gets the JSDoc type tag for the node if present and valid */
     function getJSDocTypeTag(node: Node): JSDocTypeTag | undefined;
+    function getJSDocNonNullTag(node: Node): JSDocNonNullTag | undefined;
     /**
      * Gets the type node for the node if provided via JSDoc.
      *
@@ -3721,6 +3726,7 @@ declare namespace ts {
     function isJSDocParameterTag(node: Node): node is JSDocParameterTag;
     function isJSDocReturnTag(node: Node): node is JSDocReturnTag;
     function isJSDocTypeTag(node: Node): node is JSDocTypeTag;
+    function jsJSDocNonNullTag(node: Node): node is JSDocNonNullTag;
     function isJSDocTemplateTag(node: Node): node is JSDocTemplateTag;
     function isJSDocTypedefTag(node: Node): node is JSDocTypedefTag;
     function isJSDocPropertyTag(node: Node): node is JSDocPropertyTag;

tests/baselines/reference/nonnulltag1.symbols

@@ -0,0 +1,23 @@
+=== tests/cases/conformance/jsdoc/a.js ===
+/**
+ * @type {(()=>string)[]}
+ */
+
+let queue = [];
+>queue : Symbol(queue, Decl(a.js, 4, 3))
+
+while (queue.length) {
+>queue.length : Symbol(Array.length, Decl(lib.es5.d.ts, --, --))
+>queue : Symbol(queue, Decl(a.js, 4, 3))
+>length : Symbol(Array.length, Decl(lib.es5.d.ts, --, --))
+
+    const top = /** @nonnull */(queue.pop());
+>top : Symbol(top, Decl(a.js, 6, 9))
+>queue.pop : Symbol(Array.pop, Decl(lib.es5.d.ts, --, --))
+>queue : Symbol(queue, Decl(a.js, 4, 3))
+>pop : Symbol(Array.pop, Decl(lib.es5.d.ts, --, --))
+
+    top();
+>top : Symbol(top, Decl(a.js, 6, 9))
+}
+

tests/baselines/reference/nonnulltag1.types

@@ -0,0 +1,27 @@
+=== tests/cases/conformance/jsdoc/a.js ===
+/**
+ * @type {(()=>string)[]}
+ */
+
+let queue = [];
+>queue : (() => string)[]
+>[] : never[]
+
+while (queue.length) {
+>queue.length : number
+>queue : (() => string)[]
+>length : number
+
+    const top = /** @nonnull */(queue.pop());
+>top : (() => string) | undefined
+>(queue.pop()) : (() => string) | undefined
+>queue.pop() : (() => string) | undefined
+>queue.pop : () => (() => string) | undefined
+>queue : (() => string)[]
+>pop : () => (() => string) | undefined
+
+    top();
+>top() : string
+>top : () => string
+}
+

tests/baselines/reference/nonnulltag2.symbols

@@ -0,0 +1,38 @@
+=== tests/cases/conformance/jsdoc/a.js ===
+class ElementWrapper {
+>ElementWrapper : Symbol(ElementWrapper, Decl(a.js, 0, 0))
+
+    /**
+     * @type {string}
+     * @nonnull
+     */
+    element
+>element : Symbol(ElementWrapper.element, Decl(a.js, 0, 22))
+
+    constructor() {
+        this.init();
+>this.init : Symbol(ElementWrapper.init, Decl(a.js, 9, 5))
+>this : Symbol(ElementWrapper, Decl(a.js, 0, 0))
+>init : Symbol(ElementWrapper.init, Decl(a.js, 9, 5))
+    }
+
+    init() {
+>init : Symbol(ElementWrapper.init, Decl(a.js, 9, 5))
+
+        this.element = "123"
+>this.element : Symbol(ElementWrapper.element, Decl(a.js, 0, 22))
+>this : Symbol(ElementWrapper, Decl(a.js, 0, 0))
+>element : Symbol(ElementWrapper.element, Decl(a.js, 0, 22))
+    }
+
+    getElementStyle() {
+>getElementStyle : Symbol(ElementWrapper.getElementStyle, Decl(a.js, 13, 5))
+
+        this.element.toLowerCase() // error: element is possibly undefined
+>this.element.toLowerCase : Symbol(String.toLowerCase, Decl(lib.es5.d.ts, --, --))
+>this.element : Symbol(ElementWrapper.element, Decl(a.js, 0, 22))
+>this : Symbol(ElementWrapper, Decl(a.js, 0, 0))
+>element : Symbol(ElementWrapper.element, Decl(a.js, 0, 22))
+>toLowerCase : Symbol(String.toLowerCase, Decl(lib.es5.d.ts, --, --))
+    }
+}

tests/baselines/reference/nonnulltag2.types

@@ -0,0 +1,42 @@
+=== tests/cases/conformance/jsdoc/a.js ===
+class ElementWrapper {
+>ElementWrapper : ElementWrapper
+
+    /**
+     * @type {string}
+     * @nonnull
+     */
+    element
+>element : string
+
+    constructor() {
+        this.init();
+>this.init() : void
+>this.init : () => void
+>this : this
+>init : () => void
+    }
+
+    init() {
+>init : () => void
+
+        this.element = "123"
+>this.element = "123" : "123"
+>this.element : string
+>this : this
+>element : string
+>"123" : "123"
+    }
+
+    getElementStyle() {
+>getElementStyle : () => void
+
+        this.element.toLowerCase() // error: element is possibly undefined
+>this.element.toLowerCase() : string
+>this.element.toLowerCase : () => string
+>this.element : string
+>this : this
+>element : string
+>toLowerCase : () => string
+    }
+}

tests/cases/conformance/jsdoc/nonnulltag1.ts

@@ -0,0 +1,15 @@
+// @noEmit: true
+// @allowJs: true
+// @checkJs: true
+// @strict: true
+// @Filename: a.js
+
+/**
+ * @type {(()=>string)[]}
+ */
+
+let queue = [];
+while (queue.length) {
+    const top = /** @nonnull */(queue.pop());
+    top();
+}

tests/cases/conformance/jsdoc/nonnulltag2.ts

@@ -0,0 +1,25 @@
+// @noEmit: true
+// @allowJs: true
+// @checkJs: true
+// @strict: true
+// @Filename: a.js
+
+class ElementWrapper {
+    /**
+     * @type {string}
+     * @nonnull
+     */
+    element
+
+    constructor() {
+        this.init();
+    }
+
+    init() {
+        this.element = "123"
+    }
+
+    getElementStyle() {
+        this.element.toLowerCase() // error: element is possibly undefined
+    }
+}