Merge pull request #482 from sveltejs/gh-481

allow helpers to depend on one another

src/generators/Generator.js

@@ -9,7 +9,7 @@ import { removeNode, removeObjectKey } from '../utils/removeNode.js';
 import getIntro from './shared/utils/getIntro.js';
 import getOutro from './shared/utils/getOutro.js';
 import processCss from './shared/processCss.js';
-import annotateWithScopes from './annotateWithScopes.js';
+import annotateWithScopes from '../utils/annotateWithScopes.js';
 
 const test = typeof global !== 'undefined' && global.__svelte_test;
 

src/generators/dom/index.js

@@ -1,3 +1,8 @@
+import MagicString from 'magic-string';
+import { parse } from 'acorn';
+import annotateWithScopes from '../../utils/annotateWithScopes.js';
+import isReference from '../../utils/isReference.js';
+import { walk } from 'estree-walker';
 import deindent from '../../utils/deindent.js';
 import CodeBuilder from '../../utils/CodeBuilder.js';
 import visit from './visit.js';
@@ -296,8 +301,36 @@ export default function dom ( parsed, source, options ) {
 		);
 	} else {
 		generator.uses.forEach( key => {
-			const fn = shared[ key ]; // eslint-disable-line import/namespace
-			builders.main.addBlock( fn.toString().replace( /^function [^(]*/, 'function ' + generator.alias( key ) ) );
+			const str = shared[ key ].toString(); // eslint-disable-line import/namespace
+			const code = new MagicString( str );
+			const fn = parse( str ).body[0];
+
+			let scope = annotateWithScopes( fn );
+
+			walk( fn, {
+				enter ( node, parent ) {
+					if ( node._scope ) scope = node._scope;
+
+					if ( node.type === 'Identifier' && isReference( node, parent ) && !scope.has( node.name ) ) {
+						if ( node.name in shared ) {
+							// this helper function depends on another one
+							generator.uses.add( node.name );
+
+							const alias = generator.alias( node.name );
+							if ( alias !== node.name ) code.overwrite( node.start, node.end, alias );
+						}
+					}
+				},
+
+				leave ( node ) {
+					if ( node._scope ) scope = scope.parent;
+				}
+			});
+
+			const alias = generator.alias( fn.id.name );
+			if ( alias !== fn.id.name ) code.overwrite( fn.id.start, fn.id.end, alias );
+
+			builders.main.addBlock( code.toString() );
 		});
 	}
 

src/shared/index.js

@@ -23,18 +23,18 @@ export function dispatchObservers ( component, group, newState, oldState ) {
 		var newValue = newState[ key ];
 		var oldValue = oldState[ key ];
 
-		if ( newValue === oldValue && typeof newValue !== 'object' ) continue;
-
-		var callbacks = group[ key ];
-		if ( !callbacks ) continue;
-
-		for ( var i = 0; i < callbacks.length; i += 1 ) {
-			var callback = callbacks[i];
-			if ( callback.__calling ) continue;
-
-			callback.__calling = true;
-			callback.call( component, newValue, oldValue );
-			callback.__calling = false;
+		if ( differs( newValue, oldValue ) ) {
+			var callbacks = group[ key ];
+			if ( !callbacks ) continue;
+
+			for ( var i = 0; i < callbacks.length; i += 1 ) {
+				var callback = callbacks[i];
+				if ( callback.__calling ) continue;
+
+				callback.__calling = true;
+				callback.call( component, newValue, oldValue );
+				callback.__calling = false;
+			}
 		}
 	}
 }

src/shared/methods.js

@@ -39,22 +39,7 @@ export function observeDev ( key, callback, options ) {
 		throw new Error( message );
 	}
 
-	var group = ( options && options.defer ) ? this._observers.pre : this._observers.post;
-
-	( group[ key ] || ( group[ key ] = [] ) ).push( callback );
-
-	if ( !options || options.init !== false ) {
-		callback.__calling = true;
-		callback.call( this, this._state[ key ] );
-		callback.__calling = false;
-	}
-
-	return {
-		cancel: function () {
-			var index = group[ key ].indexOf( callback );
-			if ( ~index ) group[ key ].splice( index, 1 );
-		}
-	};
+	return observe.call( this, key, callback, options );
 }
 
 export function on ( eventName, handler ) {
@@ -77,15 +62,7 @@ export function onDev ( eventName, handler ) {
 		return this.on( 'destroy', handler );
 	}
 
-	var handlers = this._handlers[ eventName ] || ( this._handlers[ eventName ] = [] );
-	handlers.push( handler );
-
-	return {
-		cancel: function () {
-			var index = handlers.indexOf( handler );
-			if ( ~index ) handlers.splice( index, 1 );
-		}
-	};
+	return on.call( this, eventName, handler );
 }
 
 export function set ( newState ) {