Added proper formatting of unexpeted function call error

kcwiakala · Dec 4, 2017 · 5574b94 · 5574b94
1 parent 9c9e4a9
commit 5574b94
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Showing 2 changed files with 39 additions and 2 deletions.
diff --git a/lib/mock.js b/lib/mock.js
@@ -6,6 +6,36 @@ const check = require('./check');
 
 class UnexpectedCall extends Error {};
 
+function formatArgument(arg) {
+  switch(typeof arg) {
+    case 'string':
+      return '"' + arg + '"';
+    case 'function':
+      return 'function';
+    case 'number':
+    case 'boolean':
+    case 'undefined':
+      return '' + arg;
+    case 'object':
+      if(arg === null) {
+        return 'null';
+      } else if(_.isArray(arg)) {
+        return '[...]';
+      } 
+      return '{...}';
+  }
+}
+
+function formatCall(functionName, args) {
+  let output = functionName + '(';
+  let formattedArgs = [];
+  for(let i in args) {
+    formattedArgs.push(formatArgument(args[i]));
+  }
+  output += formattedArgs.join(',') + ')';
+  return output;
+}
+
 /** @class Mock
  * 
  */
@@ -38,11 +68,11 @@ class Mock {
     const args = Array.from(arguments).slice(1);
     const expectations = this.expectations[functionName];
     if(!expectations || expectations.length === 0) {
-      throw new UnexpectedCall('Unexpected call of ' + functionName);
+      throw new UnexpectedCall('Unexpected call of ' + formatCall(functionName, args));
     }
     const idx = _.findIndex(expectations, exp => exp.isMatching(args) && !exp.isSaturated());
     if(idx < 0) {
-      throw new UnexpectedCall('No matching expectation for call ' + functionName + '(' + args.join(',') + ')' );
+      throw new UnexpectedCall('No matching expectation for call ' + formatCall(functionName, args));
     } else {
       return expectations[idx].execute(args);
     }

diff --git a/test/mock.js b/test/mock.js
@@ -58,6 +58,13 @@ describe('Mock', () => {
       expect(a.foo(1,2)).to.be.equal(4);
       expect(a.foo.bind(a, 2, 1)).to.throw(UnexpectedCall, 'No matching expectation');
     });
+
+    it('Should throw exception with proper formatting of failed call', () => {
+      let a = new A();
+      let aMock = new Mock(a);
+      expect(() => a.foo('Hello', {x:1, y:2}, [1,2,3], false)).to.throw(UnexpectedCall, 'foo("Hello",{...},[...],false)');
+      expect(() => a.bar(1.23, null, undefined, a.bar)).to.throw(UnexpectedCall, 'bar(1.23,null,undefined,function)');
+    });
   });
 
   describe('verify', () => {