Supporting a new set methods

.github/workflows/build_and_test.yml

@@ -15,10 +15,10 @@ jobs:
       - name: Checkout Repo
         uses: actions/checkout@master
 
-      - name: Setup Node.js 20.x
+      - name: Setup Node.js 22.x
         uses: actions/setup-node@master
         with:
-          node-version: 20.x
+          node-version: 22.x
 
       - name: Install Dependencies
         run: yarn --frozen-lockfile --ignore-scripts

.github/workflows/coveralls.yml

@@ -13,10 +13,10 @@ jobs:
           # This makes Actions fetch all Git history so that Changesets can generate changelogs with the correct commits
           fetch-depth: 0
 
-      - name: Setup Node.js 20.x
+      - name: Setup Node.js 22.x
         uses: actions/setup-node@master
         with:
-          node-version: 20.x
+          node-version: 22.x
 
       - name: Install Dependencies
         run: yarn --frozen-lockfile --ignore-scripts

docs/installation.md

@@ -50,7 +50,7 @@ For verification insert this piece of code at the beginning of your sources (eg.
 if (!new class { x }().hasOwnProperty('x')) throw new Error('Transpiler is not configured correctly');
 ```
 
-Note that for Next.js you must [customize Babel](https://nextjs.org/docs/advanced-features/customizing-babel-config) instead of TypeScript, even if your project is set up to use TypeScript. 
+Note that for Next.js you must [customize Babel](https://nextjs.org/docs/advanced-features/customizing-babel-config) instead of TypeScript, even if your project is set up to use TypeScript.
 
 ## MobX on older JavaScript environments
 

package.json

@@ -6,7 +6,7 @@
     ],
     "resolutions": {
         "jest": "^29.5.0",
-        "typescript": "^5.0.2",
+        "typescript": "^5.5.2",
         "recast": "^0.23.1"
     },
     "repository": {
@@ -68,7 +68,7 @@
         "tape": "^5.0.1",
         "ts-jest": "^29.0.5",
         "tsdx": "^0.14.1",
-        "typescript": "^5.0.2"
+        "typescript": "^5.5.2"
     },
     "husky": {
         "hooks": {

packages/mobx/CHANGELOG.md

@@ -1396,7 +1396,7 @@ A deprecation message will now be printed if creating computed properties while
 
 ```javascript
 const x = observable({
-    computedProp: function() {
+    computedProp: function () {
         return someComputation
     }
 })
@@ -1421,7 +1421,7 @@ or alternatively:
 
 ```javascript
 observable({
-    computedProp: computed(function() {
+    computedProp: computed(function () {
         return someComputation
     })
 })
@@ -1439,7 +1439,7 @@ N.B. If you want to introduce actions on an observable that modify its state, us
 ```javascript
 observable({
     counter: 0,
-    increment: action(function() {
+    increment: action(function () {
         this.counter++
     })
 })
@@ -1565,10 +1565,10 @@ function Square() {
     extendObservable(this, {
         length: 2,
         squared: computed(
-            function() {
+            function () {
                 return this.squared * this.squared
             },
-            function(surfaceSize) {
+            function (surfaceSize) {
                 this.length = Math.sqrt(surfaceSize)
             }
         )

packages/mobx/__tests__/v5/base/set.js

@@ -289,3 +289,142 @@ test("set.forEach is reactive", () => {
     s.add(2)
     expect(c).toBe(3)
 })
+
+describe("The Set object methods do what they are supposed to do", () => {
+    const reactiveSet = set([1, 2, 3, 4, 5])
+
+    test("Observable Set methods returns correct result", () => {
+        const intersectionObservableResult = reactiveSet.intersection(new Set([1, 2, 6]))
+        const unionObservableResult = reactiveSet.union(new Set([1, 2, 6]))
+        const differenceObservableResult = reactiveSet.difference(new Set([1, 2, 3, 4, 5, 6, 7]))
+        const symmetricDifferenceObservableResult = reactiveSet.symmetricDifference(new Set([3, 4]))
+        const isSubsetOfObservableResult = reactiveSet.isSubsetOf(new Set([1, 2, 3]))
+        const isSupersetOfObservableResult = reactiveSet.isSupersetOf(new Set([1, 2, 3, 4, 5, 6]))
+        const isDisjointFromObservableResult = reactiveSet.isDisjointFrom(new Set([6, 7]))
+
+        expect(intersectionObservableResult).toEqual(new Set([1, 2]))
+        expect(unionObservableResult).toEqual(new Set([1, 2, 3, 4, 5, 6]))
+        expect(differenceObservableResult).toEqual(new Set())
+        expect(symmetricDifferenceObservableResult).toEqual(new Set([1, 2, 5]))
+        expect(isSubsetOfObservableResult).toBeFalsy()
+        expect(isSupersetOfObservableResult).toBeFalsy()
+        expect(isDisjointFromObservableResult).toBeTruthy()
+    })
+
+    test("Observable Set proper works with Set-like objects", () => {
+        const intersectionObservableResult = reactiveSet.intersection(
+            new Map([1, 2, 6].map(i => [i, i]))
+        )
+        const unionObservableResult = reactiveSet.union(new Map([1, 2, 6].map(i => [i, i])))
+        const differenceObservableResult = reactiveSet.difference(
+            new Map([1, 2, 3, 4, 5, 6, 7].map(i => [i, i]))
+        )
+        const symmetricDifferenceObservableResult = reactiveSet.symmetricDifference(
+            new Map([3, 4].map(i => [i, i]))
+        )
+        const isSubsetOfObservableResult = reactiveSet.isSubsetOf(
+            new Map([1, 2, 3].map(i => [i, i]))
+        )
+        const isSupersetOfObservableResult = reactiveSet.isSupersetOf(
+            new Map([1, 2, 3, 4, 5, 6].map(i => [i, i]))
+        )
+        const isDisjointFromObservableResult = reactiveSet.isDisjointFrom(
+            new Map([6, 7].map(i => [i, i]))
+        )
+
+        expect(intersectionObservableResult).toEqual(new Set([1, 2]))
+        expect(unionObservableResult).toEqual(new Set([1, 2, 3, 4, 5, 6]))
+        expect(differenceObservableResult).toEqual(new Set())
+        expect(symmetricDifferenceObservableResult).toEqual(new Set([1, 2, 5]))
+        expect(isSubsetOfObservableResult).toBeFalsy()
+        expect(isSupersetOfObservableResult).toBeFalsy()
+        expect(isDisjointFromObservableResult).toBeTruthy()
+    })
+})
+
+describe("Observable Set methods are reactive", () => {
+    let c = 0
+    let s = set()
+
+    beforeEach(() => {
+        c = 0
+        s = set()
+    })
+
+    test("Intersection method is reactive", () => {
+        autorun(() => {
+            s.intersection(new Set())
+            c++
+        })
+
+        s.add(1)
+        s.add(2)
+        expect(c).toBe(3)
+    })
+
+    test("Union method is reactive", () => {
+        autorun(() => {
+            s.union(new Set())
+            c++
+        })
+
+        s.add(1)
+        s.add(2)
+        expect(c).toBe(3)
+    })
+
+    test("Difference method is reactive", () => {
+        autorun(() => {
+            s.difference(new Set())
+            c++
+        })
+
+        s.add(1)
+        s.add(2)
+        expect(c).toBe(3)
+    })
+
+    test("symmetricDifference method is reactive", () => {
+        autorun(() => {
+            s.symmetricDifference(new Set())
+            c++
+        })
+
+        s.add(1)
+        s.add(2)
+        expect(c).toBe(3)
+    })
+
+    test("isSubsetOf method is reactive", () => {
+        autorun(() => {
+            s.isSubsetOf(new Set())
+            c++
+        })
+
+        s.add(1)
+        s.add(2)
+        expect(c).toBe(3)
+    })
+
+    test("isSupersetOf method is reactive", () => {
+        autorun(() => {
+            s.isSupersetOf(new Set())
+            c++
+        })
+
+        s.add(1)
+        s.add(2)
+        expect(c).toBe(3)
+    })
+
+    test("isDisjointFrom method is reactive", () => {
+        autorun(() => {
+            s.isDisjointFrom(new Set())
+            c++
+        })
+
+        s.add(1)
+        s.add(2)
+        expect(c).toBe(3)
+    })
+})

packages/mobx/src/types/observableset.ts

@@ -243,6 +243,58 @@ export class ObservableSet<T = any> implements Set<T>, IInterceptable<ISetWillCh
         } as any)
     }
 
+    intersection<U>(otherSet: ReadonlySetLike<U> | Set<U>): Set<T & U> {
+        if (isES6Set(otherSet)) {
+            this.atom_.reportObserved()
+            return otherSet.intersection(this.data_)
+        } else {
+            const dehancedSet = new Set(this)
+            return dehancedSet.intersection(otherSet)
+        }
+    }
+
+    union<U>(otherSet: ReadonlySetLike<U> | Set<U>): Set<T | U> {
+        if (isES6Set(otherSet)) {
+            this.atom_.reportObserved()
+            return otherSet.union(this.data_)
+        } else {
+            const dehancedSet = new Set(this)
+            return dehancedSet.union(otherSet)
+        }
+    }
+
+    difference<U>(otherSet: ReadonlySetLike<U>): Set<T> {
+        return new Set(this).difference(otherSet)
+    }
+
+    symmetricDifference<U>(otherSet: ReadonlySetLike<U> | Set<U>): Set<T | U> {
+        if (isES6Set(otherSet)) {
+            this.atom_.reportObserved()
+            return otherSet.symmetricDifference(this.data_)
+        } else {
+            const dehancedSet = new Set(this)
+            return dehancedSet.symmetricDifference(otherSet)
+        }
+    }
+
+    isSubsetOf(otherSet: ReadonlySetLike<unknown>): boolean {
+        return new Set(this).isSubsetOf(otherSet)
+    }
+
+    isSupersetOf(otherSet: ReadonlySetLike<unknown>): boolean {
+        return new Set(this).isSupersetOf(otherSet)
+    }
+
+    isDisjointFrom(otherSet: ReadonlySetLike<unknown> | Set<unknown>): boolean {
+        if (isES6Set(otherSet)) {
+            this.atom_.reportObserved()
+            return otherSet.isDisjointFrom(this.data_)
+        } else {
+            const dehancedSet = new Set(this)
+            return dehancedSet.isDisjointFrom(otherSet)
+        }
+    }
+
     replace(other: ObservableSet<T> | IObservableSetInitialValues<T>): ObservableSet<T> {
         if (isObservableSet(other)) {
             other = new Set(other)

tsconfig.json

@@ -3,7 +3,7 @@
         "target": "es6",
         "module": "esnext",
         "moduleResolution": "node",
-        "lib": ["es6"],
+        "lib": ["esnext"],
         "downlevelIteration": true,
         "alwaysStrict": true,
         "sourceMap": true,