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Cherry-pick PR #34987 into release-3.7 (#35303)

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5810765259 Emit defineProperty calls before param prop assignments
Note that I restricted this to --useDefineForClassFields is true.
Nothing changes when it's off. I think this is the correct fix for a
patch release.

However, in principal there's nothing wrong with moving parameter
property initialisation after property declaration initialisation. It
would be Extremely Bad and Wrong to rely on this working:

```ts
class C {
  p = this.q // what is q?
  constructor(public q: number) { }
}
```

But today it does, and probably somebody relies on it without knowing.

ec7959091a Put parameter property initialiser into defineProperty's value

be863550b7 Merge branch 'master' into fix-defineProperty-parameter-property-emit

8ff59b98b8 Combine ES5/ESNext into one test
This commit is contained in:
TypeScript Bot
2019-11-22 16:26:51 -08:00
committed by Nathan Shively-Sanders
parent d5bcb6f904
commit c021b28597
14 changed files with 356 additions and 207 deletions
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src/compiler/transformers/classFields.ts
+17 -18
View File
@@ -10,9 +10,9 @@ namespace ts {
/**
* Transforms ECMAScript Class Syntax.
* TypeScript parameter property syntax is transformed in the TypeScript transformer.
* For now, this transforms public field declarations using TypeScript class semantics
* (where the declarations get elided and initializers are transformed as assignments in the constructor).
* Eventually, this transform will change to the ECMAScript semantics (with Object.defineProperty).
* For now, this transforms public field declarations using TypeScript class semantics,
* where declarations are elided and initializers are transformed as assignments in the constructor.
* When --useDefineForClassFields is on, this transforms to ECMAScript semantics, with Object.defineProperty.
*/
export function transformClassFields(context: TransformationContext) {
const {
@@ -294,7 +294,8 @@ namespace ts {
}
function transformConstructorBody(node: ClassDeclaration | ClassExpression, constructor: ConstructorDeclaration | undefined, isDerivedClass: boolean) {
const properties = getProperties(node, /*requireInitializer*/ !context.getCompilerOptions().useDefineForClassFields, /*isStatic*/ false);
const useDefineForClassFields = context.getCompilerOptions().useDefineForClassFields;
const properties = getProperties(node, /*requireInitializer*/ !useDefineForClassFields, /*isStatic*/ false);
// Only generate synthetic constructor when there are property initializers to move.
if (!constructor && !some(properties)) {
@@ -325,7 +326,6 @@ namespace ts {
if (constructor) {
indexOfFirstStatement = addPrologueDirectivesAndInitialSuperCall(constructor, statements, visitor);
}
// Add the property initializers. Transforms this:
//
// public x = 1;
@@ -336,19 +336,16 @@ namespace ts {
// this.x = 1;
// }
//
if (constructor && constructor.body) {
let parameterPropertyDeclarationCount = 0;
for (let i = indexOfFirstStatement; i < constructor.body.statements.length; i++) {
if (isParameterPropertyDeclaration(getOriginalNode(constructor.body.statements[i]), constructor)) {
parameterPropertyDeclarationCount++;
}
else {
break;
}
if (constructor?.body) {
let afterParameterProperties = findIndex(constructor.body.statements, s => !isParameterPropertyDeclaration(getOriginalNode(s), constructor), indexOfFirstStatement);
if (afterParameterProperties === -1) {
afterParameterProperties = constructor.body.statements.length;
}
if (parameterPropertyDeclarationCount > 0) {
addRange(statements, visitNodes(constructor.body.statements, visitor, isStatement, indexOfFirstStatement, parameterPropertyDeclarationCount));
indexOfFirstStatement += parameterPropertyDeclarationCount;
if (afterParameterProperties > indexOfFirstStatement) {
if (!useDefineForClassFields) {
addRange(statements, visitNodes(constructor.body.statements, visitor, isStatement, indexOfFirstStatement, afterParameterProperties - indexOfFirstStatement));
}
indexOfFirstStatement = afterParameterProperties;
}
}
addPropertyStatements(statements, properties, createThis());
@@ -421,7 +418,9 @@ namespace ts {
? updateComputedPropertyName(property.name, getGeneratedNameForNode(property.name))
: property.name;
const initializer = property.initializer || emitAssignment ? visitNode(property.initializer, visitor, isExpression) : createVoidZero();
const initializer = property.initializer || emitAssignment ? visitNode(property.initializer, visitor, isExpression)
: hasModifier(getOriginalNode(property), ModifierFlags.ParameterPropertyModifier) && isIdentifier(propertyName) ? propertyName
: createVoidZero();
if (emitAssignment) {
const memberAccess = createMemberAccessForPropertyName(receiver, propertyName, /*location*/ propertyName);
return createAssignment(memberAccess, initializer);
src/compiler/transformers/ts.ts
+2 -2
View File
@@ -900,13 +900,13 @@ namespace ts {
if (parametersWithPropertyAssignments) {
for (const parameter of parametersWithPropertyAssignments) {
if (isIdentifier(parameter.name)) {
members.push(aggregateTransformFlags(createProperty(
members.push(setOriginalNode(aggregateTransformFlags(createProperty(
/*decorators*/ undefined,
/*modifiers*/ undefined,
parameter.name,
/*questionOrExclamationToken*/ undefined,
/*type*/ undefined,
/*initializer*/ undefined)));
/*initializer*/ undefined)), parameter));
}
}
}