feat: Introduce way to get property value from dictionary and throw i…

…f it does not exist

package.json

@@ -48,7 +48,8 @@
     "typescript": "^4.5.4",
     "husky": "^7.0.4",
     "@commitlint/cli": "^16.1.0",
-    "@commitlint/config-conventional": "^16.0.0"
+    "@commitlint/config-conventional": "^16.0.0",
+    "type-fest": "^2.12.0"
   },
   "bugs": {
     "url": "https://github.com/ogre-works/ogre-tools/issues"

packages/fp/ogre-tools-fp.d.ts

@@ -1,4 +1,6 @@
 declare module '@ogre-tools/fp' {
+  import { Get } from 'type-fest';
+
   interface Pipeline {
     <A, R1, R2, R3, R4, R5, R6, R7, R8, R9>(
       arg: A,
@@ -76,4 +78,18 @@ declare module '@ogre-tools/fp' {
   }
 
   export const pipeline: Pipeline;
+
+  interface GetFrom {
+    <TDictionary, TPropertyPath extends string>(
+      dictionary: TDictionary,
+      propertyPath: TPropertyPath,
+    ): Get<TDictionary, TPropertyPath>;
+
+    <TDictionary>(dictionary: TDictionary): <TPropertyPath extends string>(
+      propertyPath: TPropertyPath,
+    ) => Get<TDictionary, TPropertyPath>;
+  }
+
+  export const getFrom: GetFrom;
+  export const getSafeFrom: GetFrom;
 }

packages/fp/src/getFrom/getFrom.js

@@ -0,0 +1,6 @@
+import curry from 'lodash/fp/curry';
+import get from 'lodash/fp/get';
+
+export default curry((dictionary, propertyName) =>
+  get(propertyName, dictionary),
+);

packages/fp/src/getFrom/getFrom.test.js

@@ -0,0 +1,23 @@
+import getSafeFrom from './getFrom';
+
+describe('getSafeFrom', () => {
+  it('when getting existing value, returns value', () => {
+    const actual = getSafeFrom({ someProperty: 'some-value' })('someProperty');
+
+    expect(actual).toBe('some-value');
+  });
+
+  it('when getting non existing value, return undefined', () => {
+    const actual = getSafeFrom({})('someNonExistingProperty');
+
+    expect(actual).toBeUndefined();
+  });
+
+  it('when getting existing nested value, returns value', () => {
+    const actual = getSafeFrom({ someRoot: { someProperty: 'some-value' } })(
+      'someRoot.someProperty',
+    );
+
+    expect(actual).toBe('some-value');
+  });
+});

packages/fp/src/getSafeFrom/getSafeFrom.js

@@ -0,0 +1,11 @@
+import curry from 'lodash/fp/curry';
+import get from 'lodash/fp/get';
+import has from 'lodash/fp/has';
+
+export default curry((dictionary, propertyName) => {
+  if (!has(propertyName, dictionary)) {
+    throw new Error(`Tried to get unknown property "${propertyName}"`);
+  }
+
+  return get(propertyName, dictionary);
+});

packages/fp/src/getSafeFrom/getSafeFrom.test.js

@@ -0,0 +1,23 @@
+import getSafeFrom from './getSafeFrom';
+
+describe('getSafeFrom', () => {
+  it('when getting existing value, returns value', () => {
+    const actual = getSafeFrom({ someProperty: 'some-value' })('someProperty');
+
+    expect(actual).toBe('some-value');
+  });
+
+  it('when getting non existing value, throws', () => {
+    expect(() => {
+      getSafeFrom({})('someNonExistingProperty');
+    }).toThrow('Tried to get unknown property "someNonExistingProperty"');
+  });
+
+  it('when getting existing nested value, returns value', () => {
+    const actual = getSafeFrom({ someRoot: { someProperty: 'some-value' } })(
+      'someRoot.someProperty',
+    );
+
+    expect(actual).toBe('some-value');
+  });
+});