fix(typescript/readTypeScriptModules): getReturnType should cope with computed initializers

Closes #187

Author: davidreher

typescript/mocks/readTypeScriptModules/getReturnType.ts

@@ -0,0 +1,11 @@
+export class Parent {
+  someProp = {
+    foo: 'bar',
+  };
+}
+
+export class Child extends Parent {
+  someProp = Object.assign(this.someProp, {
+    bar: 'baz'
+  });
+}

typescript/processors/readTypeScriptModules.js

@@ -383,10 +383,16 @@ module.exports = function readTypeScriptModules(tsParser, modules, getFileInfo,
       // The symbol does not have a "type" but it is being initialized
       // so we can deduce the type of from the initializer (mostly).
       if (declaration.initializer.expression) {
-        return declaration.initializer.expression.text.trim();
-      } else {
-        return getType(sourceFile, declaration.initializer).trim();
+        var initializerExpressionText = declaration.initializer.expression.text;
+        var intrinsicNameFromTypeChecker = typeChecker.getTypeOfSymbolAtLocation(symbol, sourceFile).intrinsicName;
+        // we might not have an expression text.
+        if (initializerExpressionText) {
+          return initializerExpressionText.replace(/\s+/g, ' ').trim();
+        } else if (intrinsicNameFromTypeChecker) {
+          return intrinsicNameFromTypeChecker.trim();
+        }
       }
+      return getType(sourceFile, declaration.initializer).trim();
     }
   }
 

typescript/processors/readTypeScriptModules.spec.js

@@ -180,6 +180,23 @@ describe('readTypeScriptModules', function() {
       expect(moduleDoc.name).toEqual('privateModule');
     });
   });
+  
+  describe('getReturnType', function () {
+    it('should not throw if "declaration.initializer.expression.text" is undefined', function () {
+      processor.sourceFiles = ['getReturnType.ts'];      
+      var docs = [];
+      expect(function () { processor.$process(docs); }).not.toThrow();
+    });
+
+    it('should try get the type from the typeChecker if possible', function () {
+      processor.sourceFiles = ['getReturnType.ts'];      
+      var docs = [];
+      processor.$process(docs);
+      
+      var overriddenSomePropDoc = _.last(docs);
+      expect(overriddenSomePropDoc.returnType).toEqual('any');
+    });
+  });
 });
 
 function getNames(collection) {