make abstract removeNode function

Author: Rich-Harris

src/generators/Generator.js

@@ -4,6 +4,7 @@ import isReference from '../utils/isReference.js';
 import flattenReference from '../utils/flattenReference.js';
 import globalWhitelist from '../utils/globalWhitelist.js';
 import reservedNames from '../utils/reservedNames.js';
+import { removeNode } from '../utils/removeNode.js';
 import getIntro from './shared/utils/getIntro.js';
 import getOutro from './shared/utils/getOutro.js';
 import processCss from './shared/processCss.js';
@@ -268,28 +269,25 @@ export default class Generator {
 
 		if ( js ) {
 			this.addSourcemapLocations( js.content );
+			const body = js.content.body.slice(); // slice, because we're going to be mutating the original
 
 			// imports need to be hoisted out of the IIFE
-			for ( let i = 0; i < js.content.body.length; i += 1 ) {
-				const node = js.content.body[i];
+			for ( let i = 0; i < body.length; i += 1 ) {
+				const node = body[i];
 				if ( node.type === 'ImportDeclaration' ) {
-					let a = node.start;
-					let b = node.end;
-					while ( /[ \t]/.test( source[ a - 1 ] ) ) a -= 1;
-					while ( source[b] === '\n' ) b += 1;
-
+					removeNode( this.code, js.content, node );
 					imports.push( node );
-					this.code.remove( a, b );
+
 					node.specifiers.forEach( specifier => {
 						this.importedNames.add( specifier.local.name );
 					});
 				}
 			}
 
-			defaultExport = js.content.body.find( node => node.type === 'ExportDefaultDeclaration' );
+			defaultExport = body.find( node => node.type === 'ExportDefaultDeclaration' );
 
 			if ( defaultExport ) {
-				const finalNode = js.content.body[ js.content.body.length - 1 ];
+				const finalNode = body[ body.length - 1 ];
 				if ( defaultExport === finalNode ) {
 					// export is last property, we can just return it
 					this.code.overwrite( defaultExport.start, defaultExport.declaration.start, `return ` );

src/generators/dom/index.js

@@ -2,7 +2,7 @@ import deindent from '../../utils/deindent.js';
 import getBuilders from './utils/getBuilders.js';
 import CodeBuilder from '../../utils/CodeBuilder.js';
 import namespaces from '../../utils/namespaces.js';
-import removeObjectKey from '../../utils/removeObjectKey.js';
+import { removeObjectKey } from '../../utils/removeNode.js';
 import visitors from './visitors/index.js';
 import Generator from '../Generator.js';
 import * as shared from '../../shared/index.js';
@@ -175,7 +175,7 @@ export default function dom ( parsed, source, options ) {
 		const ns = templateProperties.namespace.value.value;
 		namespace = namespaces[ ns ] || ns;
 
-		removeObjectKey( generator, defaultExport.declaration, 'namespace' );
+		removeObjectKey( generator.code, defaultExport.declaration, 'namespace' );
 	}
 
 	if ( templateProperties.components ) {
@@ -192,11 +192,11 @@ export default function dom ( parsed, source, options ) {
 		if ( hasNonImportedComponent ) {
 			// remove the specific components that were imported, as we'll refer to them directly
 			Array.from( generator.importedComponents.keys() ).forEach( key => {
-				removeObjectKey( generator, templateProperties.components.value, key );
+				removeObjectKey( generator.code, templateProperties.components.value, key );
 			});
 		} else {
 			// remove the entire components portion of the export
-			removeObjectKey( generator, defaultExport.declaration, 'components' );
+			removeObjectKey( generator.code, defaultExport.declaration, 'components' );
 		}
 	}
 

src/utils/removeNode.js

@@ -0,0 +1,55 @@
+const keys = {
+	ObjectExpression: 'properties',
+	Program: 'body'
+};
+
+const offsets = {
+	ObjectExpression: [ 1, -1 ],
+	Program: [ 0, 0 ]
+};
+
+export function removeNode ( code, parent, node ) {
+	const key = keys[ parent.type ];
+	const offset = offsets[ parent.type ];
+	if ( !key || !offset ) throw new Error( `not implemented: ${parent.type}` );
+
+	const list = parent[ key ];
+	const i = list.indexOf( node );
+	if ( i === -1 ) throw new Error( 'node not in list' );
+
+	let a;
+	let b;
+
+	if ( list.length === 1 ) {
+		// remove everything, leave {}
+		a = parent.start + offset[0];
+		b = parent.end + offset[1];
+	} else if ( i === 0 ) {
+		// remove everything before second node, including comments
+		a = parent.start + offset[0];
+		while ( /\s/.test( code.original[a] ) ) a += 1;
+
+		b = list[i].end;
+		while ( /[\s,]/.test( code.original[b] ) ) b += 1;
+	} else {
+		// remove the end of the previous node to the end of this one
+		a = list[ i - 1 ].end;
+		b = node.end;
+	}
+
+	code.remove( a, b );
+	list.splice( i, 1 );
+	return;
+}
+
+export function removeObjectKey ( code, node, key ) {
+	if ( node.type !== 'ObjectExpression' ) return;
+
+	let i = node.properties.length;
+	while ( i-- ) {
+		const property = node.properties[i];
+		if ( property.key.type === 'Identifier' && property.key.name === key ) {
+			removeNode( code, node, property );
+		}
+	}
+}