com.google.javascript.jscomp.modules.Binding Maven / Gradle / Ivy
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/*
* Copyright 2018 The Closure Compiler Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.javascript.jscomp.modules;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import com.google.auto.value.AutoValue;
import com.google.common.base.Preconditions;
import com.google.javascript.jscomp.modules.ModuleMetadataMap.ModuleMetadata;
import com.google.javascript.rhino.Node;
import javax.annotation.Nullable;
/**
* Represents a variable bound by an import or export statement, or goog.require. This can either be
* a single variable or a entire module namespace created by an import * statement.
*
* See {@link Module#namespace()} and {@link Module#boundNames()} for how Bindings are used.
*/
@AutoValue
public abstract class Binding {
// Prevent unwanted subclasses.
Binding() {}
/** Different ways that Bindings can be created. */
enum CreatedBy {
/**
* A binding created by an export in an ES module.
*
*
* export const x = 0;
* export function x() {}
* export {x};
* export * from ''; // creates bindings in the namespace
*
*/
EXPORT,
/**
* A binding created by an ES import.
*
*
* import {x} from '';
* import * as x from '';
* import x from '';
*
*/
IMPORT,
/**
* A binding created by a goog.require statement.
*
*
* const x = goog.require();
* const {x} = goog.require();
*
*/
GOOG_REQUIRE,
/**
* A binding created by a goog.requireType statement.
*
*
* const x = goog.requireType();
* const {x} = goog.requireType();
*
*/
GOOG_REQUIRE_TYPE,
/**
* A binding created by a goog.forwardDeclare statement.
*
*
* const x = goog.forwardDeclare();
* const {x} = goog.forwardDeclare();
*
*/
GOOG_FORWARD_DECLARE;
/** Whether this is some goog.* dependency import */
boolean isClosureImport() {
return this.equals(GOOG_REQUIRE)
|| this.equals(GOOG_REQUIRE_TYPE)
|| this.equals(GOOG_FORWARD_DECLARE);
}
}
/** Binding for an exported value that is not a module namespace object. */
static Binding from(Export boundExport, Node sourceNode) {
return new AutoValue_Binding(
boundExport.moduleMetadata(),
sourceNode,
boundExport,
/* isModuleNamespace= */ false,
/* closureNamespace= */ null,
CreatedBy.EXPORT);
}
/** Binding for an entire module namespace created by const x = goog.require(Type)('...') */
static Binding from(
ModuleMetadata metadata, Node sourceNode, String closureNamespace, CreatedBy createdBy) {
Preconditions.checkArgument(
createdBy.isClosureImport(),
"Expected goog.require(Type) or goog.forwardDeclare, got %s",
createdBy);
return new AutoValue_Binding(
metadata,
sourceNode,
/* originatingExport= */ null,
/* isModuleNamespace= */ true,
closureNamespace,
createdBy);
}
/** Binding for an entire module namespace created by an import *. */
static Binding from(
ModuleMetadata metadataOfBoundModule, @Nullable String closureNamespace, Node sourceNode) {
return new AutoValue_Binding(
metadataOfBoundModule,
sourceNode,
/* originatingExport= */ null,
/* isModuleNamespace= */ true,
closureNamespace,
CreatedBy.IMPORT);
}
/** Copies the binding with a new source node and CreatedBy binding. */
Binding copy(Node sourceNode, CreatedBy createdBy) {
checkNotNull(sourceNode);
return new AutoValue_Binding(
metadata(),
sourceNode,
originatingExport(),
isModuleNamespace(),
closureNamespace(),
createdBy);
}
/**
* Metadata of the module this is bound to.
*
* If this was made from an {@code import *} then it is the module that this imported.
* Otherwise it is the module this binding was created in (e.g. the module of the originating
* export).
*/
public abstract ModuleMetadata metadata();
/**
* The AST node to use for source location when rewriting.
*
*
This is generally a NAME or IMPORT_STAR node inside an import or export statement that
* represents where the name was bound. However as {@code export * from} has no NAME nodes the
* source node in that instance should be the entire export node.
*
*
Null for missing ES modules and non-ES modules as they are currently not scanned.
*/
@Nullable
public abstract Node sourceNode();
/**
* Returns the original export if this binding was created by an export.
*
*
For transitive exports this will still be the *original* export, not the transitive link.
*/
@Nullable
public abstract Export originatingExport();
/** True if this represents a module namespace, e.g. created by {@code import *} */
public abstract boolean isModuleNamespace();
@Nullable
public abstract String closureNamespace();
public abstract CreatedBy createdBy();
/**
* The name of the variable this export is bound to, assuming it is not a binding of a module
* namespace.
*/
public final String boundName() {
checkState(!isModuleNamespace());
return originatingExport().localName();
}
/**
* Returns whether or not this export is potentially mutated after module execution (i.e. in a
* function scope).
*/
public final boolean isMutated() {
// Module namespaces can never be mutated. They are always imported, and import bound names
// are const.
return !isModuleNamespace() && originatingExport().mutated();
}
/**
* Returns whether this Binding originated from an ES import, as opposed to an export or
* goog.require.
*/
public final boolean isCreatedByEsImport() {
return createdBy().equals(CreatedBy.IMPORT);
}
}