Refactor to enforce strictNullChecks

This commit applies `strictNullChecks` to the entire codebase to improve
maintainability and type safety. Key changes include:

- Remove some explicit null-checks where unnecessary.
- Add necessary null-checks.
- Refactor static factory functions for a more functional approach.
- Improve some test names and contexts for better debugging.
- Add unit tests for any additional logic introduced.
- Refactor `createPositionFromRegexFullMatch` to its own function as the
  logic is reused.
- Prefer `find` prefix on functions that may return `undefined` and
  `get` prefix for those that always return a value.

tests/unit/application/Parser/ScriptingDefinition/CodeSubstituter.spec.ts

@@ -3,40 +3,21 @@ import { CodeSubstituter } from '@/application/Parser/ScriptingDefinition/CodeSu
 import { IExpressionsCompiler } from '@/application/Parser/Script/Compiler/Expressions/IExpressionsCompiler';
 import { ProjectInformationStub } from '@tests/unit/shared/Stubs/ProjectInformationStub';
 import { ExpressionsCompilerStub } from '@tests/unit/shared/Stubs/ExpressionsCompilerStub';
-import { getAbsentObjectTestCases, getAbsentStringTestCases } from '@tests/unit/shared/TestCases/AbsentTests';
+import { itEachAbsentStringValue } from '@tests/unit/shared/TestCases/AbsentTests';
 
 describe('CodeSubstituter', () => {
-  describe('throws with invalid parameters', () => {
-    // arrange
-    const testCases = [
-      ...getAbsentStringTestCases().map((testCase) => ({
-        name: `given code: ${testCase.valueName}`,
-        expectedError: 'missing code',
-        parameters: {
-          code: testCase.absentValue,
-          info: new ProjectInformationStub(),
-        },
-      })),
-      ...getAbsentObjectTestCases().map((testCase) => ({
-        name: `given info: ${testCase.valueName}`,
-        expectedError: 'missing info',
-        parameters: {
-          code: 'non empty code',
-          info: testCase.absentValue,
-        },
-      })),
-    ];
-    for (const testCase of testCases) {
-      it(`${testCase.name} throws "${testCase.expectedError}"`, () => {
-        // arrange
-        const sut = new CodeSubstituterBuilder().build();
-        const { code, info } = testCase.parameters;
-        // act
-        const act = () => sut.substitute(code, info);
-        // assert
-        expect(act).to.throw(testCase.expectedError);
-      });
-    }
+  describe('throws if code is empty', () => {
+    itEachAbsentStringValue((emptyCode) => {
+      // arrange
+      const expectedError = 'missing code';
+      const code = emptyCode;
+      const info = new ProjectInformationStub();
+      const sut = new CodeSubstituterBuilder().build();
+      // act
+      const act = () => sut.substitute(code, info);
+      // assert
+      expect(act).to.throw(expectedError);
+    }, { excludeNull: true, excludeUndefined: true });
   });
   describe('substitutes parameters as expected values', () => {
     // arrange