Added error handling for loops, warps, etc. Fixes #50

src/backend.js

@@ -60,11 +60,14 @@ backend.bounceOffEdge = function(node) {
 ///////////////////// Control /////////////////////
 backend.doWarp = function(node) {
     let body = this.generateCode(node.inputs[0]);
-    let afterFn = `callback_${node.id}_${Date.now()}`;
-    return `new SPromise(${afterFn} => ${callStatementWithArgs(node.type, true)}
+    const afterFn = `callback_${node.id}_${Date.now()}`;
+    const reject = `reject_${node.id}_${Date.now()}`;
+
+    return `new SPromise((${afterFn}, ${reject}) => ${callStatementWithArgs(node.type, true)}
         .then(() => ${body})
         .then(() => ${callStatementWithArgs(node.type, false)})
         .then(() => ${afterFn}())
+        .catch(${reject})
     )`;
 
 };
@@ -73,6 +76,8 @@ backend.doWait = function(node) {
     var time = this.generateCode(node.inputs[0]),
         afterFn = `afterWait_${node.id}`;
 
+    // TODO: handle rejections?
+    // This can only fail if the underlying implementation is faulty...
     return [
         `new SPromise(${afterFn} => {`,
         callStatementWithArgs(node.type, time, afterFn),
@@ -108,6 +113,7 @@ backend.doReport = function(node) {
     // Get the current callback name and call it!
     var value = this.generateCode(node.inputs[0]);
     let callback = getCallbackName(node);
+    //let reject = getRejectName(node);
     if (!node.parent) throw 'no parent:' + node.type;
 
     if (callback) {
@@ -168,22 +174,24 @@ backend.fork = function(node) {
 };
 
 backend.doRepeat = function(node) {
-    var count = node.inputs[0] ? this.generateCode(node.inputs[0]) : 0,
+    let count = node.inputs[0] ? this.generateCode(node.inputs[0]) : 0,
         body = this.generateCode(node.inputs[1]),
         next = this.generateCode(node.next),
         iterVar = node.id,
         recurse;
 
     recurse = callStatementWithArgs('doYield', `doLoop_${node.id}`, node.id);
 
-    let cond = `${node.id}-- > 0`;
-    let doLoop = `() => {${body}.then(() => ${recurse})}`;
-    let callback = `resolve_${node.id}_${Date.now()}`;
-    let doElse = `() => {${next}.then(() => ${callback}());\n}`;
+    const cond = `${node.id}-- > 0`;
+    const callback = `resolve_${node.id}_${Date.now()}`;
+    const reject = `reject_${node.id}_${Date.now()}`;
+
+    let doLoop = `() => {${body}.then(() => ${recurse}).catch(${reject})}`;
+    let doElse = `() => {${next}.then(() => ${callback}()).then(${reject});\n}`;
     loopControl = callStatementWithArgs('doIfElse', cond, doLoop, doElse);
 
     return [
-        `new SPromise(${callback} => {`,
+        `new SPromise((${callback}, ${reject}) => {`,
         `function doLoop_${node.id} (${node.id}) {`,
         `return ${indent(loopControl)};`,
         `}`,
@@ -195,16 +203,18 @@ backend.doRepeat.async = true;
 
 backend.doForever = function(node) {
     var recurse = callStatementWithArgs('doYield', `doForever_${node.id}`),
+        callback = `resolve_${node.id}_${Date.now()}`,
+        reject = `reject_${node.id}_${Date.now()}`,
         body = recurse;
 
     if (node.inputs[0]) {
-        body = `${this.generateCode(node.inputs[0])}.then(() => ${recurse})`;
+        body = `${this.generateCode(node.inputs[0])}.then(() => ${recurse}).catch(${reject})`;
     } else {
         body = recurse;
     }
 
     return [
-        `new SPromise(() => {`,
+        `new SPromise((${callback}, ${reject}) => {`,
         `function doForever_${node.id} () {`,
         indent(body),
         `}`,
@@ -218,6 +228,7 @@ backend.doUntil = function(node) {
         body = newPromise(),
         exitBody = node.next ? this.generateCode(node.next) : newPromise(),
         callback = `resolve_${node.id}_${Date.now()}`,
+        reject = `reject_${node.id}_${Date.now()}`,
         iterVar = node.id,
         recurse;
 
@@ -231,12 +242,12 @@ backend.doUntil = function(node) {
         cond = this.generateCode(node.inputs[0]);
     }
 
-    let execBody = `function() {\n${body}.then(() => ${recurse})}`;
-    let exitLoop = `function() {\n${exitBody}.then(() => \n${callback}());\n}`;
+    let execBody = `function() {\n${body}.then(() => ${recurse}).catch(${reject})}`;
+    let exitLoop = `function() {\n${exitBody}.then(() => \n${callback}()).then(${reject});\n}`;
 
     loopControl = callStatementWithArgs('doIfElse', cond, exitLoop, execBody);
     return [
-        `new SPromise(${callback} => {`,
+        `new SPromise((${callback}, ${reject}) => {`,
         `function doLoop_${node.id} () {`,
         `${indent(loopControl)};`,
         `}`,
@@ -290,6 +301,8 @@ backend.doSayFor = function(node) {
         msg = this.generateCode(node.inputs[0]),
         afterFn = `afterSay_${node.id}`;
 
+    // TODO: handle rejections?
+    // This can only fail if the underlying implementation is faulty...
     return [
         `new SPromise(${afterFn} => {`,
         callStatementWithArgs(node.type, msg, time, afterFn),
@@ -302,6 +315,8 @@ backend.doThinkFor = function(node) {
         msg = this.generateCode(node.inputs[0]),
         afterFn = `afterThink_${node.id}`;
 
+    // TODO: handle rejections?
+    // This can only fail if the underlying implementation is faulty...
     return [
         `new SPromise(${afterFn} => {`,
         callStatementWithArgs(node.type, msg, time, afterFn),
@@ -478,40 +493,60 @@ const TYPES_WITH_CALLBACKS = [
 let nodeIdCounter = 1;
 
 // Get the name of the callback fn of the closest enclosing fn definition
-const getCallbackName = node => {
+const getFnName = (fn, node) => {
     if (TYPES_WITH_CALLBACKS.includes(node.type)) {
         if (!node.id) {
             node.id = `anon_item__${nodeIdCounter++}`;
         }
-        return `callback${node.id.replace(/-/g, '_')}`;
+        return `${fn}${node.id.replace(/-/g, '_')}`;
     }
 
-    if (node.parent) return getCallbackName(node.parent);
+    if (node.parent) return getFnName(fn, node.parent);
 
     return null;
 };
 
+const getCallbackName = node => getFnName('callback', node);
+const getRejectName = node => getFnName('reject', node);
+
+
 backend.reifyScript =
 backend.reifyReporter =
 backend.reifyPredicate = function(node) {
-    var body = '',
+    let body = '',
         cb = getCallbackName(node),
+        reject = getRejectName(node),
         args = node.inputs[1].inputs
             .map(this.generateCode);
 
+    // Why is this missing the callback???
     if (node.inputs[0]) {
         body = this.generateCode(node.inputs[0]);
+
+        // Add error handling and callback
+        let lastChar = body[body.length-1];
+
+        let isMissingCallback = !(new RegExp('\\b' + cb + '\\b').test(body));
+        if (isMissingCallback) {
+            body = body.replace(/[;\n]*$/, `.then(${cb})`);
+        }
+
+        body = body.replace(/[;\n]*$/, `.catch(${reject})`);
+        if (lastChar === ';') body += ';';
+    } else {
+        body = `${cb}()`;
     }
 
-    // TODO: add the callback name to the function...
     // TODO: doReport should call this callback...
     return [
-        `function(${args.map((e, i) => `a${i}`).join(', ')}${args.length ? ',' : ''}${cb}) {`,
-        indent(`var context = new VariableFrame(arguments[${args.length+1}] || __CONTEXT);`),
+        `function(${args.map((e, i) => `a${i}`).join(', ')}) {`,
+        indent(`return new SPromise((${cb}, ${reject}) => {`),
+        indent(`var context = new VariableFrame(arguments[${args.length}] || __CONTEXT);`),
         indent(`var self = context.get('${CALLER}').value;`),
         indent(args.map((arg, index) => `context.set(${arg}, a${index});`).join('\n')),
         indent(`__CONTEXT = context;`),
         indent(body),
+        indent(`});`),
         `}`
     ].join('\n');
 };
@@ -526,7 +561,7 @@ backend.autolambda = function(node) {
     let callback = getCallbackName(node);
 
     if (callback) {
-        body = `${callback}(${body});`;
+        body = `SPromise.resolve().then(() => ${body}).then(${callback});`;
     }
 
     return `return ${body};`;

src/context/basic.js

@@ -463,24 +463,14 @@ context.reportJoinWords = function() {
 
 context.evaluate = function(fn) {
     var args = Array.prototype.slice.call(arguments, 1);
-    return new SPromise(resolve => {
-        let cxt = args.pop();
-        args.push(resolve);
-        args.push(cxt);
-        return fn.apply(this, args);
-    });
+    return fn.apply(this, args);
 };
 
 context.evaluateCustomBlock = function(name, fnVar) {
     var args = Array.prototype.slice.call(arguments, 2),
         fn = fnVar.value;
 
-    return new SPromise(resolve => {
-        let cxt = args.pop();
-        args.push(resolve);
-        args.push(cxt);
-        return fn.apply(this, args);
-    });
+    return fn.apply(this, args);
 };
 
 module.exports = context;

test/compilation.spec.js

@@ -11,6 +11,7 @@ describe('compilation', function() {
 
     utils.getProjectPaths()
         .filter(filename => !filename.includes('all-control'))
+        //.filter(filename => filename.includes('custom-block-inputs'))
         .forEach(filename => {
             it(`should nop every operation in ${filename}`, function() {
                 var content = fs.readFileSync(filename, 'utf8');

test/compile-fns.spec.js

@@ -76,7 +76,7 @@ describe('functions', function() {
             let factory = snap2js.compile(content);
             let env = snap2js.newContext();
             let fn = factory(env);
-            fn.call(null, result => {
+            fn().then(result => {
                 result.forEach((n, i) => assert.equal(n, i+1));
                 done();
             });

test/custom-blocks.spec.js

@@ -47,11 +47,9 @@ describe('custom blocks', function() {
                     assert(value(result[index]));
                 } else if (value instanceof Object) {
                     fn = result[index];
-                    return fn(value.in, promise => {
-                        promise.then(output => {
-                            assert.equal(output, value.out);
-                            done();
-                        });
+                    return fn(value.in).then(output => {
+                        assert.equal(output, value.out);
+                        done();
                     });
                 } else {
                     assert.equal(result[index], value);

test/errors.spec.js

@@ -0,0 +1,74 @@
+describe('errors', function() {
+    const snap2js = require('..');
+    const assert = require('assert');
+    const utils = require('./utils');
+    const Q = require('q');
+
+    describe('basic', function() {
+        it('should be able to catch error', function(done) {
+            let cxt = snap2js.newContext();
+            let content = utils.getContextXml('list-err');
+            let bin = snap2js.compile(content);
+            let fn = bin(cxt);
+            fn().catch(err => done())
+        });
+
+        it.skip('should return the failing block id', function() {
+            let cxt = snap2js.newContext();
+
+            let content = utils.getContextXml('list-err');
+            console.log(snap2js.transpile(content));
+
+            let bin = snap2js.compile(content);
+            let fn = bin(cxt);
+            console.log(fn.toString());
+            try {
+                Q(fn())
+                    .catch(err => console.error('error:', err));
+                console.log('no error');
+            } catch (e) {
+                console.log('err', e);
+            }
+        });
+    });
+
+    describe('in repeat loop', function() {
+        it('should be able to catch error', function(done) {
+            let cxt = snap2js.newContext();
+            let content = utils.getContextXml('list-err-loop');
+            let bin = snap2js.compile(content);
+            let fn = bin(cxt);
+            fn().catch(err => done())
+        });
+    });
+
+    describe('in repeat until', function() {
+        it('should be able to catch error', function(done) {
+            let cxt = snap2js.newContext();
+            let content = utils.getContextXml('list-err-until');
+            let bin = snap2js.compile(content);
+            let fn = bin(cxt);
+            fn().catch(err => done())
+        });
+    });
+
+    describe('in forever', function() {
+        it('should be able to catch error', function(done) {
+            let cxt = snap2js.newContext();
+            let content = utils.getContextXml('list-err-forever');
+            let bin = snap2js.compile(content);
+            let fn = bin(cxt);
+            fn().catch(err => done())
+        });
+    });
+
+    describe('in warp', function() {
+        it('should be able to catch error', function(done) {
+            let cxt = snap2js.newContext();
+            let content = utils.getContextXml('list-err-warp');
+            let bin = snap2js.compile(content);
+            let fn = bin(cxt);
+            fn().catch(err => done())
+        });
+    });
+});

test/operators.spec.js

@@ -177,20 +177,16 @@ describe('operators', function() {
             });
 
             it('should eval true correctly (and+and+not)', function(done) {
-                result(true, true, false, result => {
-                    result.then(value => {
-                        assert.equal(value, true);
-                        done();
-                    });
+                result(true, true, false).then(value => {
+                    assert.equal(value, true);
+                    done();
                 });
             });
 
             it('should eval false correctly (and+and+not)', function(done) {
-                result(true, true, true, result => {
-                    result.then(value => {
-                        assert.equal(value, false);
-                        done();
-                    });
+                result(true, true, true).then(value => {
+                    assert.equal(value, false);
+                    done();
                 });
             });
         });
@@ -207,11 +203,9 @@ describe('operators', function() {
             });
 
             it('should eval correctly (sum inputs)', function(done) {
-                result(3, 5, promise => {
-                    promise.then(value => {
-                        assert.equal(value, 8);
-                        done();
-                    });
+                result(3, 5).then(value => {
+                    assert.equal(value, 8);
+                    done();
                 });
             });
         });

test/test-cases/contexts/list-err-forever.xml

@@ -0,0 +1 @@
+<context id="1"><inputs></inputs><variables></variables><script><block collabId="item_25_2" s="doDeclareVariables"><list><l>a</l></list></block><block collabId="item_26" s="doForever"><script><block collabId="item_25_6" s="doChangeVar"><l>a</l><l>2</l></block><block collabId="item_25_7" s="doAddToList"><l>thing</l><block collabId="item_25_10" var="a"/></block></script></block></script><receiver><sprite name="Sprite" collabId="item_-1" idx="1" x="0" y="0" heading="90" scale="1" rotation="1" draggable="true" costume="0" color="80,80,80" pen="tip" id="17"><costumes><list collabId="" id="18"></list></costumes><sounds><list collabId="" id="19"></list></sounds><variables></variables><blocks></blocks><scripts><script x="183" y="197"><block collabId="item_2" s="getJSFromRPCStruct"><l>Execute</l><l>call</l><block collabId="item_6" s="reifyScript"><script><block collabId="item_8" s="doDeclareVariables"><list><l>a</l></list></block><block collabId="item_13" s="doRepeat"><l>10</l><script><block collabId="item_9" s="doChangeVar"><l>a</l><l>2</l></block><block collabId="item_18" s="doAddToList"><l>thing</l><block collabId="item_19" var="a"/></block></script></block><block collabId="item_7" s="doReport"><block collabId="item_12" var="a"/></block></script><list></list></block></block></script><script x="200" y="427"><block collabId="item_20" s="getJSFromRPCStruct"><l>Execute</l><l>call</l><block collabId="item_20_1" s="reifyScript"><script><block collabId="item_20_2" s="doDeclareVariables"><list><l>a</l></list></block><block collabId="item_20_3" s="doUntil"><block collabId="item_22" s="reportLessThan"><l>10</l><block collabId="item_23" var="a"/></block><script><block collabId="item_20_5" s="doChangeVar"><l>a</l><l>2</l></block><block collabId="item_20_6" s="doAddToList"><l>thing</l><block collabId="item_20_8" var="a"/></block></script></block><block collabId="item_20_4" s="doReport"><block collabId="item_20_7" var="a"/></block></script><list></list></block></block></script><script x="647" y="430"><block collabId="item_25" s="getJSFromRPCStruct"><l>Execute</l><l>call</l><block collabId="item_25_1" s="reifyScript"><script><block collabId="item_25_2" s="doDeclareVariables"><list><l>a</l></list></block><block collabId="item_26" s="doForever"><script><block collabId="item_25_6" s="doChangeVar"><l>a</l><l>2</l></block><block collabId="item_25_7" s="doAddToList"><l>thing</l><block collabId="item_25_10" var="a"/></block></script></block></script><list></list></block></block></script><script x="725.4580098125" y="612.000005"><block collabId="item_25_3" s="doUntil"><block collabId="item_25_5" s="reportLessThan"><l>10</l><block collabId="item_25_8" var="a"/></block><script></script></block><block collabId="item_25_4" s="doReport"><block collabId="item_25_9" var="a"/></block></script></scripts><history></history></sprite></receiver><context id="106"><inputs></inputs><variables></variables><receiver><ref id="17"></ref></receiver></context></context>

test/test-cases/contexts/list-err-loop.xml

@@ -0,0 +1 @@
+<context id="1"><inputs></inputs><variables></variables><script><block collabId="item_8" s="doDeclareVariables"><list><l>a</l></list></block><block collabId="item_13" s="doRepeat"><l>10</l><script><block collabId="item_9" s="doChangeVar"><l>a</l><l>2</l></block><block collabId="item_18" s="doAddToList"><l>thing</l><block collabId="item_19" var="a"/></block></script></block><block collabId="item_7" s="doReport"><block collabId="item_12" var="a"/></block></script><receiver><sprite name="Sprite" collabId="item_-1" idx="1" x="0" y="0" heading="90" scale="1" rotation="1" draggable="true" costume="0" color="80,80,80" pen="tip" id="20"><costumes><list collabId="" id="21"></list></costumes><sounds><list collabId="" id="22"></list></sounds><variables></variables><blocks></blocks><scripts><script x="183" y="197"><block collabId="item_2" s="getJSFromRPCStruct"><l>Execute</l><l>call</l><block collabId="item_6" s="reifyScript"><script><block collabId="item_8" s="doDeclareVariables"><list><l>a</l></list></block><block collabId="item_13" s="doRepeat"><l>10</l><script><block collabId="item_9" s="doChangeVar"><l>a</l><l>2</l></block><block collabId="item_18" s="doAddToList"><l>thing</l><block collabId="item_19" var="a"/></block></script></block><block collabId="item_7" s="doReport"><block collabId="item_12" var="a"/></block></script><list></list></block></block></script></scripts><history></history></sprite></receiver><context id="51"><inputs></inputs><variables></variables><receiver><ref id="20"></ref></receiver></context></context>