refactor: emit warning for invalid & in XML (#1059)

Author: Alexander Vakrilov

Diff for: xml-namespace-loader.spec.ts

@@ -20,13 +20,15 @@ interface TestSetup {
     expectedRegs: { name: string, path: string }[],
     ignore?: RegExp,
     assureNoDeps?: boolean,
-    expectError?: boolean
+    expectError?: boolean,
+    expectWarnings?: number
 }
 
 function getContext(
     done: DoneFn,
-    { resolveMap, expectedDeps, expectedRegs, assureNoDeps, ignore, expectError }: TestSetup) {
+    { resolveMap, expectedDeps, expectedRegs, assureNoDeps, ignore, expectError, expectWarnings }: TestSetup) {
     const actualDeps: string[] = [];
+    const actualWarnings: Error[] =[]
     let callbackCalled = false;
 
     const loaderContext = {
@@ -50,6 +52,10 @@ function getContext(
                 expect(source).not.toContain("global.registerModule");
             }
 
+            if(expectWarnings){
+                expect(actualWarnings.length).toEqual(expectWarnings);
+            }
+
             if (error && !expectError) {
                 done.fail(error)
             } else if (!error && expectError) {
@@ -69,6 +75,9 @@ function getContext(
         addDependency: (dep: string) => {
             actualDeps.push(dep);
         },
+        emitWarning: (err: Error) => {
+            actualWarnings.push(err);
+        },
         query: { ignore }
     }
 
@@ -277,4 +286,30 @@ describe("XmlNamespaceLoader", () => {
 
         xmlNsLoader.call(loaderContext, testXml);
     })
+
+
+    it("with '&&', '||', '<=' and '>=' in binding expression, emits warnings, but does not fail", (done) => {
+        const resolveMap = {
+            "nativescript-ui-chart": "node_module/nativescript-ui-chart/ui-chart.js",
+        }
+
+        const expectedDeps = [];
+
+        const expectedRegs = [
+            { name: "nativescript-ui-chart", path: "nativescript-ui-chart" },
+            { name: "nativescript-ui-chart/RadCartesianChart", path: "nativescript-ui-chart" },
+        ];
+
+        const testXml = `
+        <Page xmlns="http://www.nativescript.org/tns.xsd">
+            <StackLayout xmlns:chart="nativescript-ui-chart">
+                <TextField text="{{ var1 && var2 || var1 >= var2 || var2 <= var1 }}" />
+                <chart:RadCartesianChart></chart:RadCartesianChart>
+            </StackLayout>        
+        </Page>`;
+
+        const loaderContext = getContext(done, { resolveMap, expectedDeps, expectedRegs, expectWarnings: 1 });
+
+        xmlNsLoader.call(loaderContext, testXml);
+    })
 });

Diff for: xml-namespace-loader.ts

@@ -103,8 +103,17 @@ const loader: loader.Loader = function (source: string, map) {
 
     saxParser.onopentag = (node: QualifiedTag) => { handleOpenTag(node.uri, node.local); };
     saxParser.onerror = (err) => {
+        // Do only warning about invalid character "&"" for back-compatibility
+        // as it is common to use it in a binding expression
+        if (err && 
+            err.message.indexOf("Invalid character") >= 0 && 
+            err.message.indexOf("Char: &") >= 0) {
+            this.emitWarning(err)
+        } else {
+            callbackWrapper(err);
+        }
+
         saxParser.error = null;
-        callbackWrapper(err);
     };
     saxParser.write(source).close();