move expand logic into Statement

src/Module.js

@@ -288,7 +288,7 @@ export default class Module {
 			}
 
 			if ( statement && !statement.isIncluded ) {
-				promise = this.expandStatement( statement );
+				promise = statement.expand();
 			}
 		}
 
@@ -296,52 +296,6 @@ export default class Module {
 		return this.definitionPromises[ name ];
 	}
 
-	expandStatement ( statement ) {
-		if ( statement.isIncluded ) return emptyArrayPromise;
-		statement.isIncluded = true;
-
-		let result = [];
-
-		// We have a statement, and it hasn't been included yet. First, include
-		// the statements it depends on
-		const dependencies = Object.keys( statement.dependsOn );
-
-		return sequence( dependencies, name => {
-			return this.define( name ).then( definition => {
-				result.push.apply( result, definition );
-			});
-		})
-
-		// then include the statement itself
-			.then( () => {
-				result.push( statement );
-			})
-
-		// then include any statements that could modify the
-		// thing(s) this statement defines
-			.then( () => {
-				return sequence( keys( statement.defines ), name => {
-					const modifications = has( this.modifications, name ) && this.modifications[ name ];
-
-					if ( modifications ) {
-						return sequence( modifications, statement => {
-							if ( !statement.isIncluded ) {
-								return this.expandStatement( statement )
-									.then( statements => {
-										result.push.apply( result, statements );
-									});
-							}
-						});
-					}
-				});
-			})
-
-		// the `result` is an array of statements needed to define `name`
-			.then( () => {
-				return result;
-			});
-	}
-
 	expandAllStatements ( isEntryModule ) {
 		let allStatements = [];
 
@@ -349,9 +303,9 @@ export default class Module {
 			// skip already-included statements
 			if ( statement.isIncluded ) return;
 
-			// skip import declarations
-			if ( statement.node.type === 'ImportDeclaration' ) {
-				// unless they're empty, in which case assume we're importing them for the side-effects
+			// skip import declarations...
+			if ( statement.isImportDeclaration ) {
+				// ...unless they're empty, in which case assume we're importing them for the side-effects
 				// THIS IS NOT FOOLPROOF. Probably need /*rollup: include */ or similar
 				if ( !statement.node.specifiers.length ) {
 					return this.bundle.fetchModule( statement.node.source.value, this.path )
@@ -367,24 +321,22 @@ export default class Module {
 				return;
 			}
 
-			// skip `export { foo, bar, baz }`
+			// skip `export { foo, bar, baz }`...
 			if ( statement.node.type === 'ExportNamedDeclaration' && statement.node.specifiers.length ) {
-				// but ensure they are defined, if this is the entry module
+				// ...but ensure they are defined, if this is the entry module
 				if ( isEntryModule ) {
-					return this.expandStatement( statement )
-						.then( statements => {
-							allStatements.push.apply( allStatements, statements );
-						});
+					return statement.expand().then( statements => {
+						allStatements.push.apply( allStatements, statements );
+					});
 				}
 
 				return;
 			}
 
 			// include everything else
-			return this.expandStatement( statement )
-				.then( statements => {
-					allStatements.push.apply( allStatements, statements );
-				});
+			return statement.expand().then( statements => {
+				allStatements.push.apply( allStatements, statements );
+			});
 		}).then( () => {
 			return allStatements;
 		});

src/Statement.js

@@ -1,9 +1,12 @@
 import { has, keys } from './utils/object';
+import { sequence } from './utils/promise';
 import { getName } from './utils/map-helpers';
 import getLocation from './utils/getLocation';
 import walk from './ast/walk';
 import Scope from './ast/Scope';
 
+const emptyArrayPromise = Promise.resolve([]);
+
 export default class Statement {
 	constructor ( node, magicString, module ) {
 		this.node = node;
@@ -185,6 +188,52 @@ export default class Statement {
 		}
 	}
 
+	expand () {
+		if ( this.isIncluded ) return emptyArrayPromise;
+		this.isIncluded = true;
+
+		let result = [];
+
+		// We have a statement, and it hasn't been included yet. First, include
+		// the statements it depends on
+		const dependencies = Object.keys( this.dependsOn );
+
+		return sequence( dependencies, name => {
+			return this.module.define( name ).then( definition => {
+				result.push.apply( result, definition );
+			});
+		})
+
+		// then include the statement itself
+			.then( () => {
+				result.push( this );
+			})
+
+		// then include any statements that could modify the
+		// thing(s) this statement defines
+			.then( () => {
+				return sequence( keys( this.defines ), name => {
+					const modifications = has( this.module.modifications, name ) && this.module.modifications[ name ];
+
+					if ( modifications ) {
+						return sequence( modifications, statement => {
+							if ( !statement.isIncluded ) {
+								return statement.expand()
+									.then( statements => {
+										result.push.apply( result, statements );
+									});
+							}
+						});
+					}
+				});
+			})
+
+		// the `result` is an array of statements needed to define `name`
+			.then( () => {
+				return result;
+			});
+	}
+
 	replaceIdentifiers ( names ) {
 		const magicString = this.magicString.clone().trim();
 		const replacementStack = [ names ];