refactor script compilation to make it easy to add new expressions #41 #53

tests/unit/application/Parser/Script/Compiler/Expressions/Expression/ExpressionPosition.spec.ts

@@ -0,0 +1,34 @@
+import 'mocha';
+import { expect } from 'chai';
+import { ExpressionPosition } from '@/application/Parser/Script/Compiler/Expressions/Expression/ExpressionPosition';
+
+describe('ExpressionPosition', () => {
+    describe('ctor', () => {
+        it('sets as expected', () => {
+            // arrange
+            const expectedStart = 0;
+            const expectedEnd = 5;
+            // act
+            const sut = new ExpressionPosition(expectedStart, expectedEnd);
+            // assert
+            expect(sut.start).to.equal(expectedStart);
+            expect(sut.end).to.equal(expectedEnd);
+        });
+        describe('throws when invalid', () => {
+            // arrange
+            const testCases = [
+                { start: 5, end: 5, error: 'no length (start = end = 5)' },
+                { start: 5, end: 3, error: 'start (5) after end (3)' },
+                { start: -1, end: 3, error: 'negative start position: -1' },
+            ];
+            for (const testCase of testCases) {
+                it(testCase.error, () => {
+                    // act
+                    const act = () => new ExpressionPosition(testCase.start, testCase.end);
+                    // assert
+                    expect(act).to.throw(testCase.error);
+                });
+            }
+        });
+    });
+});