immutable-assign - npm Package Compare versions

Comparing version 1.0.3 to 1.0.4

deploy/iassign.js

 "use strict";
 // Immutable Assign
-function iassign(obj, getProp, setProp, ctx) {
-    // Quick check if getProp() is valid.
+function iassign(obj, // Object to set property, it will not be modified
+    getProp, // Function to get property to be updated.
+    setProp, // Function to set property
+    ctx) {
+    // Check if getProp() is valid
     var value = getProp(obj, ctx);
     var getPropBodyText = getFuncBodyText(getProp);
-    var accessorText = getPropBodyText.substr(getPropBodyText.indexOf("return ") + 7).trim();
-    if (accessorText[accessorText.length - 1] == ";") {
-        accessorText = accessorText.substring(0, accessorText.length - 1);
-    }
-    accessorText = accessorText.trim();
+    var accessorText = getAccessorText(getPropBodyText);
     var propIndex = 0;
@@ -20,6 +19,6 @@ var propValue = undefined;
         var propNameSource = ePropNameSource.none;
-        if (dotIndex == 0) {
-            accessorText = accessorText.substr(dotIndex + 1);
-            continue;
-        }
+        // if (dotIndex == 0) {
+        //     accessorText = accessorText.substr(dotIndex + 1);
+        //     continue;
+        // }
         if (openBracketIndex > -1 && closeBracketIndex <= -1) {
@@ -53,2 +52,6 @@ throw new Error("Found open bracket but not close bracket.");
         }
+        propName = propName.trim();
+        if (propName == "") {
+            continue;
+        }
         //console.log(propName);
@@ -101,2 +104,22 @@ if (propIndex <= 0) {
 }
+function getAccessorText(bodyText) {
+    var returnIndex = bodyText.indexOf("return ");
+    if (!iassign.disableAllCheck && !iassign.disableHasReturnCheck) {
+        if (returnIndex <= -1) {
+            throw new Error("getProp() function has no 'return' keyword.");
+        }
+    }
+    if (!iassign.disableAllCheck && !iassign.disableExtraStatementCheck) {
+        var otherBodyText = bodyText.substr(0, returnIndex).trim();
+        if (otherBodyText != "") {
+            throw new Error("getProp() function has statements other than 'return': " + otherBodyText);
+        }
+    }
+    var accessorText = bodyText.substr(returnIndex + 7).trim();
+    if (accessorText[accessorText.length - 1] == ";") {
+        accessorText = accessorText.substring(0, accessorText.length - 1);
+    }
+    accessorText = accessorText.trim();
+    return accessorText;
+}
 function quickCopy(value) {
@@ -103,0 +126,0 @@ var copyValue = {};

package.json

 {
   "name": "immutable-assign",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "",
   "main": "src/iassign.js",
   "scripts": {
-    "test": "node_modules\\.bin\\istanbul cover node_modules\\jasmine\\bin\\jasmine.js"
+    "test": "node_modules\\.bin\\jasmine",
+    "cover": "node_modules\\.bin\\istanbul cover node_modules\\jasmine\\bin\\jasmine.js",
+    "build": "gulp"
   },
@@ -9,0 +11,0 @@ "author": {

README.md

 # ImmutableAssign
-Lightweight immutable helper that supports TypeScript type checking.
 
+Lightweight immutable helper that supports TypeScript type checking, and allows you to continue working with POJO (Plain Old JavaScript Object).
+
+This library is trying to solve following problems:
+
+* Most immutable JavaScript libraries try to encapsulate the data, and provide proprietary APIs to work with the data. They are more verbose than normal JavaScript syntax. E.g., map1.get('b') vs map1.b, nested2.getIn(['a', 'b', 'd']) vs nested2.a.b.d, etc.
+* Encapsulated data is no more POJO, therefore cannot be easily used with other libraries, e.g., lodash, underscore, etc.
+* [seamless-immutable](https://github.com/rtfeldman/seamless-immutable) address some of above issues when reading the properties, but still use verbose APIs to write properties.
+* [Immutability Helpers](https://facebook.github.io/react/docs/update.html) allows us work with POJO, but it has still introduced some magic keywords, such as $set, $push, etc.
+* Most importantly (in my opinion), we lost TypeScript type checking. E.g., when calling nested2.getIn(['a', 'b', 'd']), TypeScript won't be able to warn me if I changed property 'd' to 'e'.
+
+This library has only one method **iassign()**, which accept a POJO object and return you a new POJO object with specific property updated.
+
 ##Install with npm
@@ -8,11 +19,43 @@
 
+#### Function Signature
+
+```javascript
+// Return a new POJO object with property updated.
+function iassign<TObj, TProp, TContext>(
+    obj: TObj,                                          // POJO object to be getting the property from, it will not be modified.
+    getProp: (obj: TObj, context: TContext) => TProp,   // Function to get the property that needs to be updated.
+    setProp: (prop: TProp) => TProp,                    // Function to set the property.
+    ctx?: TContext): TObj;                              // (Optional) Context to be used in getProp().
+```
+
 ####Example 1: Update array
 
 ```javascript
-var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]] } } };
+var iassign = require("iassign");
+var deepFreeze = require("deep-freeze");
 
-// Calling iassign()
-var o2 = iassign(o1, function (o) { return o.a.b.c[1]; }, function (c) { c.push(101); return c; });
+var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }]], c2: {} }, b2: {} }, a2: {} };
+deepFreeze(o1); // Ensure o1 is not changed, for testing only
 
-// Verify original object has not been changed.
+//
+// Calling iassign() to increment o1.a.b.c[0][0].d
+//
+var o2 = iassign(
+    o1,
+    function (o) { return o.a.b.c[0][0]; },
+    function (ci) { ci.d++; return ci; }
+);
+```
+```javascript
+//
+// Jasmine Tests
+//
+
+// expect o1 has not been changed
+expect(o1).toEqual({ a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }]], c2: {} }, b2: {} }, a2: {} });
+
+// expect o2 inner property has been updated.
+expect(o2.a.b.c[0][0].d).toBe(12);
+
+// expect object graph for changed property in o2 is now different from (!==) o1.
 expect(o2).not.toBe(o1);
@@ -22,6 +65,12 @@ expect(o2.a).not.toBe(o1.a);
 expect(o2.a.b.c).not.toBe(o1.a.b.c);
-expect(o2.a.b.c[0]).toBe(o1.a.b.c[0]);
-expect(o2.a.b.c[1]).not.toBe(o1.a.b.c[1]);
+expect(o2.a.b.c[0]).not.toBe(o1.a.b.c[0]);
+expect(o2.a.b.c[0][0]).not.toBe(o1.a.b.c[0][0]);
+expect(o2.a.b.c[0][0].d).not.toBe(o1.a.b.c[0][0].d);
+
+// expect object graph for unchanged property in o2 is still equal to (===) o1.
+expect(o2.a2).toBe(o1.a2);
+expect(o2.a.b2).toBe(o1.a.b2);
+expect(o2.a.b.c2).toBe(o1.a.b.c2);
+expect(o2.a.b.c[0][0].e).toBe(o1.a.b.c[0][0].e);
 expect(o2.a.b.c[1][0]).toBe(o1.a.b.c[1][0]);
-expect(o2.a.b.c[1][1]).toBe(101);
 ```
@@ -32,8 +81,26 @@
 ```javascript
-var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]] } } };
+var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }]], c2: {} }, b2: {} }, a2: {} };
+deepFreeze(o1); // Ensure o1 is not changed, for testing only
 
-// Calling iassign()
-var o2 = iassign(o1, function (o) { return o.a.b.c[0][0].d; }, function (d) { return d + 1; });
+//
+// Calling iassign() to push new item to o1.a.b.c[1]
+//
+var o2 = iassign(
+    o1,
+    function (o) { return o.a.b.c[1]; },
+    function (c) { c.push(101); return c; }
+);
+```
+```javascript
+//
+// Jasmine Tests
+//
 
-// Verify original object has not been changed.
+// expect o1 has not been changed
+expect(o1).toEqual({ a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }]], c2: {} }, b2: {} }, a2: {} });
+
+// expect o2 inner property has been updated.
+expect(o2.a.b.c[1][1]).toBe(101);
+
+// expect object graph for changed property in o2 is now different from (!==) o1.
 expect(o2).not.toBe(o1);
@@ -43,6 +110,11 @@ expect(o2.a).not.toBe(o1.a);
 expect(o2.a.b.c).not.toBe(o1.a.b.c);
-expect(o2.a.b.c[0]).not.toBe(o1.a.b.c[0]);
-expect(o2.a.b.c[0][0]).not.toBe(o1.a.b.c[0][0]);
-expect(o2.a.b.c[0][0].d).not.toBe(o1.a.b.c[0][0].d);
-expect(o2.a.b.c[0][0].d).toBe(12);
+expect(o2.a.b.c[1]).not.toBe(o1.a.b.c[1]);
+
+// expect object graph for unchanged property in o2 is still equal to (===) o1.
+expect(o2.a2).toBe(o1.a2);
+expect(o2.a.b2).toBe(o1.a.b2);
+expect(o2.a.b.c2).toBe(o1.a.b.c2);
+expect(o2.a.b.c[0]).toBe(o1.a.b.c[0]);
+expect(o2.a.b.c[0][0]).toBe(o1.a.b.c[0][0]);
+expect(o2.a.b.c[1][0]).toBe(o1.a.b.c[1][0]);
 ```

spec/ImmutableAssignSpec.js

@@ -8,6 +8,13 @@ "use strict";
     it("Access array item", function () {
-        var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]] } } };
+        var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]], c2: {} }, b2: {} }, a2: {} };
         deepFreeze(o1);
-        var p1 = { a: 0 };
         var o2 = iassign(o1, function (o) { return o.a.b.c[0][0]; }, function (ci) { ci.d++; return ci; });
+        //
+        // Jasmine Tests
+        //
+        // expect o1 has not been changed
+        expect(o1).toEqual({ a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]], c2: {} }, b2: {} }, a2: {} });
+        // expect o2 inner property has been updated.
+        expect(o2.a.b.c[0][0].d).toBe(12);
+        // expect object graph for changed property in o2 is now different from (!==) o1.
         expect(o2).not.toBe(o1);
@@ -20,9 +27,22 @@ expect(o2.a).not.toBe(o1.a);
         expect(o2.a.b.c[0][0].d).not.toBe(o1.a.b.c[0][0].d);
-        expect(o2.a.b.c[0][0].d).toBe(12);
+        // expect object graph for unchanged property in o2 is still equal to (===) o1.
+        expect(o2.a2).toBe(o1.a2);
+        expect(o2.a.b2).toBe(o1.a.b2);
+        expect(o2.a.b.c2).toBe(o1.a.b.c2);
+        expect(o2.a.b.c[0][0].e).toBe(o1.a.b.c[0][0].e);
+        expect(o2.a.b.c[1][0]).toBe(o1.a.b.c[1][0]);
+        expect(o2.a.b.c[2][0]).toBe(o1.a.b.c[2][0]);
     });
     it("Access array 1", function () {
-        var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]] } } };
+        var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]], c2: {} }, b2: {} }, a2: {} };
         deepFreeze(o1);
-        var p1 = { a: 0 };
         var o2 = iassign(o1, function (o) { return o.a.b.c[1]; }, function (c) { c.push(101); return c; });
+        //
+        // Jasmine Tests
+        //
+        // expect o1 has not been changed
+        expect(o1).toEqual({ a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]], c2: {} }, b2: {} }, a2: {} });
+        // expect o2 inner property has been updated.
+        expect(o2.a.b.c[1][1]).toBe(101);
+        // expect object graph for changed property in o2 is now different from (!==) o1.
         expect(o2).not.toBe(o1);
@@ -32,6 +52,12 @@ expect(o2.a).not.toBe(o1.a);
         expect(o2.a.b.c).not.toBe(o1.a.b.c);
+        expect(o2.a.b.c[1]).not.toBe(o1.a.b.c[1]);
+        // expect object graph for unchanged property in o2 is still equal to (===) o1.
+        expect(o2.a2).toBe(o1.a2);
+        expect(o2.a.b2).toBe(o1.a.b2);
+        expect(o2.a.b.c2).toBe(o1.a.b.c2);
         expect(o2.a.b.c[0]).toBe(o1.a.b.c[0]);
-        expect(o2.a.b.c[1]).not.toBe(o1.a.b.c[1]);
+        expect(o2.a.b.c[0][0]).toBe(o1.a.b.c[0][0]);
         expect(o2.a.b.c[1][0]).toBe(o1.a.b.c[1][0]);
-        expect(o2.a.b.c[1][1]).toBe(101);
+        expect(o2.a.b.c[2]).toBe(o1.a.b.c[2]);
+        expect(o2.a.b.c[2][0]).toBe(o1.a.b.c[2][0]);
     });
@@ -41,3 +67,2 @@ it("Access array 2", function () {
         deepFreeze(o1);
-        var p1 = { a: 0 };
         var o2 = iassign(o1, function (o) { return o.a.b.c; }, function (c) { c.pop(); return c; });
@@ -55,3 +80,2 @@ expect(o2).not.toBe(o1);
         deepFreeze(o1);
-        var p1 = { a: 0 };
         var o2 = iassign(o1, function (o) { return o.a.b.c; }, function (c) { c.d++; return c; });
@@ -69,3 +93,2 @@ expect(o2).not.toBe(o1);
         deepFreeze(o1);
-        var p1 = { a: 0 };
         var o2 = iassign(o1, function (o) { return o.a.b.c[0][0].d; }, function (d) { return d + 1; });
@@ -84,3 +107,2 @@ expect(o2).not.toBe(o1);
         deepFreeze(o1);
-        var p1 = { a: 0 };
         var o2 = iassign(o1, function (o) { return o.a.b.c.f; }, function (f) { return new Date(2016, 1, 1); });
@@ -138,16 +160,15 @@ expect(o2).not.toBe(o1);
         deepFreeze(o1);
-        var p1 = { a: 0 };
         expect(function () {
-            iassign(o1, function (o) { return o.a.b.c; }, function (ci) { ci[0].push(3); return ci; }, { p1: p1 });
+            iassign(o1, function (o) { return o.a.b.c; }, function (ci) { ci[0].push(3); return ci; });
         }).toThrowError(TypeError, /Can't add property/);
         expect(function () {
-            iassign(o1, function (o) { return o.a.b.c[0]; }, function (ci) { ci[0].d++; return ci; }, { p1: p1 });
+            iassign(o1, function (o) { return o.a.b.c[0]; }, function (ci) { ci[0].d++; return ci; });
         }).toThrowError(TypeError, /Cannot assign to read only property/);
         expect(function () {
-            iassign(o1, function (o) { return o.a.b.c[0]; }, function (ci) { ci[0].g = 1; return ci; }, { p1: p1 });
+            iassign(o1, function (o) { return o.a.b.c[0]; }, function (ci) { ci[0].g = 1; return ci; });
         }).toThrowError(TypeError, /Can't add property/);
         expect(function () {
-            iassign(o1, function (o) { return o.a.b.c; }, function (ci) { ci[0].pop(); return ci; }, { p1: p1 });
+            iassign(o1, function (o) { return o.a.b.c; }, function (ci) { ci[0].pop(); return ci; });
         }).toThrowError(TypeError, /object is not extensible/);
     });
 });

spec/ImmutableAssignSpec.ts

@@ -11,8 +11,22 @@
   it("Access array item", function () {
-    var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]] } } };
+    var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]], c2: {} }, b2: {} }, a2: {} };
     deepFreeze(o1);
 
-    var p1 = { a: 0 };
-    var o2 = iassign(o1, function (o) { return o.a.b.c[0][0]; }, function (ci) { ci.d++; return ci; });
+    var o2 = iassign(
+      o1,
+      (o) => o.a.b.c[0][0],
+      (ci) => { ci.d++; return ci; }
+    );
 
+    //
+    // Jasmine Tests
+    //
+
+    // expect o1 has not been changed
+    expect(o1).toEqual({ a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]], c2: {} }, b2: {} }, a2: {} })
+
+    // expect o2 inner property has been updated.
+    expect(o2.a.b.c[0][0].d).toBe(12);
+
+    // expect object graph for changed property in o2 is now different from (!==) o1.
     expect(o2).not.toBe(o1);
@@ -25,12 +39,33 @@ expect(o2.a).not.toBe(o1.a);
     expect(o2.a.b.c[0][0].d).not.toBe(o1.a.b.c[0][0].d);
-    expect(o2.a.b.c[0][0].d).toBe(12);
+
+    // expect object graph for unchanged property in o2 is still equal to (===) o1.
+    expect(o2.a2).toBe(o1.a2);
+    expect(o2.a.b2).toBe(o1.a.b2);
+    expect(o2.a.b.c2).toBe(o1.a.b.c2);
+    expect(o2.a.b.c[0][0].e).toBe(o1.a.b.c[0][0].e);
+    expect(o2.a.b.c[1][0]).toBe(o1.a.b.c[1][0]);
+    expect(o2.a.b.c[2][0]).toBe(o1.a.b.c[2][0]);
   });
 
   it("Access array 1", function () {
-    var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]] } } };
+    var o1 = { a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]], c2: {} }, b2: {} }, a2: {} };
     deepFreeze(o1);
 
-    var p1 = { a: 0 };
-    var o2 = iassign(o1, function (o) { return o.a.b.c[1]; }, function (c) { c.push(<any>101); return c; });
+    var o2 = iassign(
+      o1,
+      (o) => o.a.b.c[1],
+      (c) => { c.push(<any>101); return c; }
+    );
 
+    //
+    // Jasmine Tests
+    //
+
+    // expect o1 has not been changed
+    expect(o1).toEqual({ a: { b: { c: [[{ d: 11, e: 12 }], [{ d: 21, e: 22 }], [{ d: 31, e: 32 }]], c2: {} }, b2: {} }, a2: {} })
+
+    // expect o2 inner property has been updated.
+    expect(o2.a.b.c[1][1]).toBe(101);
+
+    // expect object graph for changed property in o2 is now different from (!==) o1.
     expect(o2).not.toBe(o1);
@@ -40,6 +75,13 @@ expect(o2.a).not.toBe(o1.a);
     expect(o2.a.b.c).not.toBe(o1.a.b.c);
+    expect(o2.a.b.c[1]).not.toBe(o1.a.b.c[1]);
+
+    // expect object graph for unchanged property in o2 is still equal to (===) o1.
+    expect(o2.a2).toBe(o1.a2);
+    expect(o2.a.b2).toBe(o1.a.b2);
+    expect(o2.a.b.c2).toBe(o1.a.b.c2);
     expect(o2.a.b.c[0]).toBe(o1.a.b.c[0]);
-    expect(o2.a.b.c[1]).not.toBe(o1.a.b.c[1]);
+    expect(o2.a.b.c[0][0]).toBe(o1.a.b.c[0][0]);
     expect(o2.a.b.c[1][0]).toBe(o1.a.b.c[1][0]);
-    expect(o2.a.b.c[1][1]).toBe(101);
+    expect(o2.a.b.c[2]).toBe(o1.a.b.c[2]);
+    expect(o2.a.b.c[2][0]).toBe(o1.a.b.c[2][0]);
   });
@@ -51,3 +93,2 @@
 
-    var p1 = { a: 0 };
     var o2 = iassign(o1, function (o) { return o.a.b.c; }, function (c) { c.pop(); return c; });
@@ -68,3 +109,2 @@
 
-    var p1 = { a: 0 };
     let o2 = iassign(o1, (o) => o.a.b.c, (c) => { c.d++; return c });
@@ -85,3 +125,2 @@
 
-    var p1 = { a: 0 };
     let o2 = iassign(o1, (o) => o.a.b.c[0][0].d, (d) => { return d + 1; });
@@ -103,3 +142,2 @@
 
-    var p1 = { a: 0 };
     let o2 = iassign(o1, (o) => o.a.b.c.f, (f) => { return new Date(2016, 1, 1) });
@@ -169,18 +207,16 @@
 
-    var p1 = { a: 0 };
-
     expect(() => {
-      iassign(o1, function (o) { return o.a.b.c; }, function (ci) { ci[0].push(<any>3); return ci; }, { p1 });
+      iassign(o1, function (o) { return o.a.b.c; }, function (ci) { ci[0].push(<any>3); return ci; });
     }).toThrowError(TypeError, /Can't add property/);
 
     expect(() => {
-      iassign(o1, function (o) { return o.a.b.c[0]; }, function (ci) { ci[0].d++; return ci; }, { p1 });
+      iassign(o1, function (o) { return o.a.b.c[0]; }, function (ci) { ci[0].d++; return ci; });
     }).toThrowError(TypeError, /Cannot assign to read only property/);
 
     expect(() => {
-      iassign(o1, function (o) { return o.a.b.c[0]; }, function (ci) { (<any>ci[0]).g = 1; return ci; }, { p1 });
+      iassign(o1, function (o) { return o.a.b.c[0]; }, function (ci) { (<any>ci[0]).g = 1; return ci; });
     }).toThrowError(TypeError, /Can't add property/);
 
     expect(() => {
-      iassign(o1, function (o) { return o.a.b.c; }, function (ci) { ci[0].pop(); return ci; }, { p1 });
+      iassign(o1, function (o) { return o.a.b.c; }, function (ci) { ci[0].pop(); return ci; });
     }).toThrowError(TypeError, /object is not extensible/);
@@ -187,0 +223,0 @@ });

src/iassign.js

 "use strict";
 // Immutable Assign
-function iassign(obj, getProp, setProp, ctx) {
-    // Quick check if getProp() is valid.
+function iassign(obj, // Object to set property, it will not be modified
+    getProp, // Function to get property to be updated.
+    setProp, // Function to set property
+    ctx) {
+    // Check if getProp() is valid
     var value = getProp(obj, ctx);
     var getPropBodyText = getFuncBodyText(getProp);
-    var accessorText = getPropBodyText.substr(getPropBodyText.indexOf("return ") + 7).trim();
-    if (accessorText[accessorText.length - 1] == ";") {
-        accessorText = accessorText.substring(0, accessorText.length - 1);
-    }
-    accessorText = accessorText.trim();
+    var accessorText = getAccessorText(getPropBodyText);
     var propIndex = 0;
@@ -20,6 +19,6 @@ var propValue = undefined;
         var propNameSource = ePropNameSource.none;
-        if (dotIndex == 0) {
-            accessorText = accessorText.substr(dotIndex + 1);
-            continue;
-        }
+        // if (dotIndex == 0) {
+        //     accessorText = accessorText.substr(dotIndex + 1);
+        //     continue;
+        // }
         if (openBracketIndex > -1 && closeBracketIndex <= -1) {
@@ -53,2 +52,6 @@ throw new Error("Found open bracket but not close bracket.");
         }
+        propName = propName.trim();
+        if (propName == "") {
+            continue;
+        }
         //console.log(propName);
@@ -101,2 +104,22 @@ if (propIndex <= 0) {
 }
+function getAccessorText(bodyText) {
+    var returnIndex = bodyText.indexOf("return ");
+    if (!iassign.disableAllCheck && !iassign.disableHasReturnCheck) {
+        if (returnIndex <= -1) {
+            throw new Error("getProp() function has no 'return' keyword.");
+        }
+    }
+    if (!iassign.disableAllCheck && !iassign.disableExtraStatementCheck) {
+        var otherBodyText = bodyText.substr(0, returnIndex).trim();
+        if (otherBodyText != "") {
+            throw new Error("getProp() function has statements other than 'return': " + otherBodyText);
+        }
+    }
+    var accessorText = bodyText.substr(returnIndex + 7).trim();
+    if (accessorText[accessorText.length - 1] == ";") {
+        accessorText = accessorText.substring(0, accessorText.length - 1);
+    }
+    accessorText = accessorText.trim();
+    return accessorText;
+}
 function quickCopy(value) {
@@ -103,0 +126,0 @@ var copyValue = {};

src/iassign.ts

 
 // Immutable Assign
 function iassign<TObj, TProp, TContext>(
-    obj: TObj,
-    getProp: (obj: TObj, context: TContext) => TProp,
-    setProp: (prop: TProp) => TProp,
-    ctx?: TContext): TObj {
+    obj: TObj,                                          // Object to set property, it will not be modified
+    getProp: (obj: TObj, context: TContext) => TProp,   // Function to get property to be updated.
+    setProp: (prop: TProp) => TProp,                    // Function to set property
+    ctx?: TContext): TObj {                             // Context to be used in getProp() 
 
-    // Quick check if getProp() is valid.
+    // Check if getProp() is valid
     let value = getProp(obj, ctx);
 
-    var getPropBodyText = getFuncBodyText(getProp);
+    let getPropBodyText = getFuncBodyText(getProp);
+    let accessorText = getAccessorText(getPropBodyText);
 
-    let accessorText = getPropBodyText.substr(getPropBodyText.indexOf("return ") + 7).trim();
-    if (accessorText[accessorText.length - 1] == ";") {
-        accessorText = accessorText.substring(0, accessorText.length - 1);
-    }
-    accessorText = accessorText.trim();
-
     let propIndex = 0;
@@ -29,7 +24,8 @@ let propValue = undefined;
         let propNameSource = ePropNameSource.none;
-        if (dotIndex == 0) {
-            accessorText = accessorText.substr(dotIndex + 1);
-            continue;
-        }
 
+        // if (dotIndex == 0) {
+        //     accessorText = accessorText.substr(dotIndex + 1);
+        //     continue;
+        // }
+
         if (openBracketIndex > -1 && closeBracketIndex <= -1) {
@@ -67,2 +63,6 @@ throw new Error("Found open bracket but not close bracket.");
 
+        propName = propName.trim();
+        if (propName == "") {
+            continue;
+        }
         //console.log(propName);
@@ -125,2 +125,27 @@
 
+function getAccessorText(bodyText: string) {
+
+    let returnIndex = bodyText.indexOf("return ");
+
+    if (!(<any>iassign).disableAllCheck && !(<any>iassign).disableHasReturnCheck) {
+        if (returnIndex <= -1) {
+            throw new Error("getProp() function has no 'return' keyword.");
+        }
+    }
+
+    if (!(<any>iassign).disableAllCheck && !(<any>iassign).disableExtraStatementCheck) {
+        let otherBodyText = bodyText.substr(0, returnIndex).trim();
+        if (otherBodyText != "") {
+            throw new Error("getProp() function has statements other than 'return': " + otherBodyText);
+        }
+    }
+
+    let accessorText = bodyText.substr(returnIndex + 7).trim();
+    if (accessorText[accessorText.length - 1] == ";") {
+        accessorText = accessorText.substring(0, accessorText.length - 1);
+    }
+    accessorText = accessorText.trim();
+    return accessorText;
+}
+
 function quickCopy<T>(value: T): T {
@@ -127,0 +152,0 @@ let copyValue: any = {};

No alert changes

Improved metrics

Total package byte prevSize

67740

increased by28.91%

Number of package files

20

increased by5.26%

Lines of code

1437

increased by23.35%

Number of lines in readme file

117

increased by160%

No dependency changes