Improve script/category name validation

- Use better error messages with more context.
- Unify their validation logic and share tests.
- Validate also type of the name.
- Refactor node (Script/Category) parser tests for easier future
  changes and cleaner test code (using `TestBuilder` to do dirty work in
  unified way).
- Add more tests. Custom `Error` properties are compared manually due to
  `chai` not supporting deep equality checks (chaijs/chai#1065,
  chaijs/chai#1405).

tests/unit/application/Parser/CategoryParser.spec.ts

@@ -1,6 +1,7 @@
 import 'mocha';
 import { expect } from 'chai';
-import { parseCategory } from '@/application/Parser/CategoryParser';
+import type { CategoryData, CategoryOrScriptData } from '@/application/collections/';
+import { CategoryFactoryType, parseCategory } from '@/application/Parser/CategoryParser';
 import { parseScript } from '@/application/Parser/Script/ScriptParser';
 import { parseDocUrls } from '@/application/Parser/DocumentationParser';
 import { ScriptCompilerStub } from '@tests/unit/shared/Stubs/ScriptCompilerStub';
@@ -8,50 +9,136 @@ import { ScriptDataStub } from '@tests/unit/shared/Stubs/ScriptDataStub';
 import { CategoryCollectionParseContextStub } from '@tests/unit/shared/Stubs/CategoryCollectionParseContextStub';
 import { LanguageSyntaxStub } from '@tests/unit/shared/Stubs/LanguageSyntaxStub';
 import { CategoryDataStub } from '@tests/unit/shared/Stubs/CategoryDataStub';
-import { itEachAbsentCollectionValue, itEachAbsentObjectValue, itEachAbsentStringValue } from '@tests/unit/shared/TestCases/AbsentTests';
+import { itEachAbsentCollectionValue, itEachAbsentObjectValue } from '@tests/unit/shared/TestCases/AbsentTests';
+import { NodeType } from '@/application/Parser/NodeValidation/NodeType';
+import { expectThrowsNodeError, ITestScenario, NodeValidationTestRunner } from '@tests/unit/application/Parser/NodeValidation/NodeValidatorTestRunner';
+import { ICategoryCollectionParseContext } from '@/application/Parser/Script/ICategoryCollectionParseContext';
+import { Category } from '@/domain/Category';
 
 describe('CategoryParser', () => {
   describe('parseCategory', () => {
-    describe('invalid category', () => {
-      describe('throws when category data is absent', () => {
-        itEachAbsentObjectValue((absentValue) => {
-          // arrange
-          const expectedMessage = 'missing category';
-          const category = absentValue;
-          const context = new CategoryCollectionParseContextStub();
-          // act
-          const act = () => parseCategory(category, context);
-          // assert
-          expect(act).to.throw(expectedMessage);
+    describe('invalid category data', () => {
+      describe('validates script data', () => {
+        describe('satisfies shared node tests', () => {
+          new NodeValidationTestRunner()
+            .testInvalidNodeName((invalidName) => {
+              return createTest(
+                new CategoryDataStub().withName(invalidName),
+              );
+            })
+            .testMissingNodeData((node) => {
+              return createTest(node as CategoryData);
+            });
         });
+        describe('throws when category children is absent', () => {
+          itEachAbsentCollectionValue((absentValue) => {
+            // arrange
+            const categoryName = 'test';
+            const expectedMessage = `"${categoryName}" has no children.`;
+            const category = new CategoryDataStub()
+              .withName(categoryName)
+              .withChildren(absentValue);
+            // act
+            const test = createTest(category);
+            // assert
+            expectThrowsNodeError(test, expectedMessage);
+          });
+        });
+        describe('throws when category child is missing', () => {
+          new NodeValidationTestRunner()
+            .testMissingNodeData((missingNode) => {
+              // arrange
+              const invalidChildNode = missingNode;
+              const parent = new CategoryDataStub()
+                .withName('parent')
+                .withChildren([new CategoryDataStub().withName('valid child'), invalidChildNode]);
+              return ({
+                // act
+                act: () => new TestBuilder()
+                  .withData(parent)
+                  .parseCategory(),
+                // assert
+                expectedContext: {
+                  selfNode: invalidChildNode,
+                  parentNode: parent,
+                },
+              });
+            });
+        });
+        it('throws when node is neither a category or a script', () => {
+          // arrange
+          const expectedError = 'Node is neither a category or a script.';
+          const invalidChildNode = { property: 'non-empty-value' } as never as CategoryOrScriptData;
+          const parent = new CategoryDataStub()
+            .withName('parent')
+            .withChildren([new CategoryDataStub().withName('valid child'), invalidChildNode]);
+          // act
+          const test: ITestScenario = {
+            // act
+            act: () => new TestBuilder()
+              .withData(parent)
+              .parseCategory(),
+            // assert
+            expectedContext: {
+              selfNode: invalidChildNode,
+              parentNode: parent,
+            },
+          };
+          // assert
+          expectThrowsNodeError(test, expectedError);
+        });
+        describe('throws when category child is invalid category', () => {
+          new NodeValidationTestRunner().testInvalidNodeName((invalidName) => {
+            // arrange
+            const invalidChildNode = new CategoryDataStub()
+              .withName(invalidName);
+            const parent = new CategoryDataStub()
+              .withName('parent')
+              .withChildren([new CategoryDataStub().withName('valid child'), invalidChildNode]);
+            return ({
+              // act
+              act: () => new TestBuilder()
+                .withData(parent)
+                .parseCategory(),
+              // assert
+              expectedContext: {
+                type: NodeType.Category,
+                selfNode: invalidChildNode,
+                parentNode: parent,
+              },
+            });
+          });
+        });
+        function createTest(category: CategoryData): ITestScenario {
+          return {
+            act: () => new TestBuilder()
+              .withData(category)
+              .parseCategory(),
+            expectedContext: {
+              type: NodeType.Category,
+              selfNode: category,
+            },
+          };
+        }
       });
-      describe('throws when category children is absent', () => {
-        itEachAbsentCollectionValue((absentValue) => {
-          // arrange
-          const categoryName = 'test';
-          const expectedMessage = `category has no children: "${categoryName}"`;
-          const category = new CategoryDataStub()
-            .withName(categoryName)
-            .withChildren(absentValue);
-          const context = new CategoryCollectionParseContextStub();
-          // act
-          const act = () => parseCategory(category, context);
-          // assert
-          expect(act).to.throw(expectedMessage);
-        });
-      });
-      describe('throws when name is absent', () => {
-        itEachAbsentStringValue((absentValue) => {
-          // arrange
-          const expectedMessage = 'category has no name';
-          const category = new CategoryDataStub()
-            .withName(absentValue);
-          const context = new CategoryCollectionParseContextStub();
-          // act
-          const act = () => parseCategory(category, context);
-          // assert
-          expect(act).to.throw(expectedMessage);
-        });
+      it(`rethrows exception if ${Category.name} cannot be constructed`, () => {
+        // arrange
+        const expectedError = 'category creation failed';
+        const factoryMock: CategoryFactoryType = () => { throw new Error(expectedError); };
+        const data = new CategoryDataStub();
+        // act
+        const act = () => new TestBuilder()
+          .withData(data)
+          .withFactory(factoryMock)
+          .parseCategory();
+        // expect
+        expectThrowsNodeError({
+          act,
+          expectedContext: {
+            type: NodeType.Category,
+            selfNode: data,
+          },
+        }, expectedError);
       });
     });
     describe('throws when context is absent', () => {
@@ -59,9 +146,10 @@ describe('CategoryParser', () => {
         // arrange
         const expectedError = 'missing context';
         const context = absentValue;
-        const category = new CategoryDataStub();
         // act
-        const act = () => parseCategory(category, context);
+        const act = () => new TestBuilder()
+          .withContext(context)
+          .parseCategory();
         // assert
         expect(act).to.throw(expectedError);
       });
@@ -72,9 +160,11 @@ describe('CategoryParser', () => {
       const expected = parseDocUrls({ docs: url });
       const category = new CategoryDataStub()
         .withDocs(url);
-      const context = new CategoryCollectionParseContextStub();
       // act
-      const actual = parseCategory(category, context).documentationUrls;
+      const actual = new TestBuilder()
+        .withData(category)
+        .parseCategory()
+        .documentationUrls;
       // assert
       expect(actual).to.deep.equal(expected);
     });
@@ -87,7 +177,11 @@ describe('CategoryParser', () => {
         const category = new CategoryDataStub()
           .withChildren([script]);
         // act
-        const actual = parseCategory(category, context).scripts;
+        const actual = new TestBuilder()
+          .withData(category)
+          .withContext(context)
+          .parseCategory()
+          .scripts;
         // assert
         expect(actual).to.deep.equal(expected);
       });
@@ -102,7 +196,11 @@ describe('CategoryParser', () => {
         const category = new CategoryDataStub()
           .withChildren([script]);
         // act
-        const actual = parseCategory(category, context).scripts;
+        const actual = new TestBuilder()
+          .withData(category)
+          .withContext(context)
+          .parseCategory()
+          .scripts;
         // assert
         expect(actual).to.deep.equal(expected);
       });
@@ -118,7 +216,11 @@ describe('CategoryParser', () => {
           .withCompiler(compiler);
         const expected = scripts.map((script) => parseScript(script, context));
         // act
-        const actual = parseCategory(category, context).scripts;
+        const actual = new TestBuilder()
+          .withData(category)
+          .withContext(context)
+          .parseCategory()
+          .scripts;
         // assert
         expect(actual).to.deep.equal(expected);
       });
@@ -139,7 +241,11 @@ describe('CategoryParser', () => {
               ]),
           ]);
         // act
-        const act = () => parseCategory(category, parseContext).scripts;
+        const act = () => new TestBuilder()
+          .withData(category)
+          .withContext(parseContext)
+          .parseCategory()
+          .scripts;
         // assert
         expect(act).to.not.throw();
       });
@@ -153,9 +259,11 @@ describe('CategoryParser', () => {
       const category = new CategoryDataStub()
         .withName('category name')
         .withChildren(expected);
-      const context = new CategoryCollectionParseContextStub();
       // act
-      const actual = parseCategory(category, context).subCategories;
+      const actual = new TestBuilder()
+        .withData(category)
+        .parseCategory()
+        .subCategories;
       // assert
       expect(actual).to.have.lengthOf(1);
       expect(actual[0].name).to.equal(expected[0].category);
@@ -163,3 +271,30 @@ describe('CategoryParser', () => {
     });
   });
 });
+
+class TestBuilder {
+  private data: CategoryData = new CategoryDataStub();
+
+  private context: ICategoryCollectionParseContext = new CategoryCollectionParseContextStub();
+
+  private factory: CategoryFactoryType = undefined;
+
+  public withData(data: CategoryData) {
+    this.data = data;
+    return this;
+  }
+
+  public withContext(context: ICategoryCollectionParseContext) {
+    this.context = context;
+    return this;
+  }
+
+  public withFactory(factory: CategoryFactoryType) {
+    this.factory = factory;
+    return this;
+  }
+
+  public parseCategory() {
+    return parseCategory(this.data, this.context, this.factory);
+  }
+}

tests/unit/application/Parser/NodeValidation/NodeDataError.spec.ts

@@ -0,0 +1,67 @@
+import 'mocha';
+import { expect } from 'chai';
+import { INodeDataErrorContext, NodeDataError } from '@/application/Parser/NodeValidation/NodeDataError';
+import { NodeDataErrorContextStub } from '@tests/unit/shared/Stubs/NodeDataErrorContextStub';
+import { NodeType } from '@/application/Parser/NodeValidation/NodeType';
+
+describe('NodeDataError', () => {
+  it('sets message as expected', () => {
+    // arrange
+    const message = 'message';
+    const context = new NodeDataErrorContextStub();
+    const expected = `[${NodeType[context.type]}] ${message}`;
+    // act
+    const sut = new NodeDataErrorBuilder()
+      .withContext(context)
+      .withMessage(expected)
+      .build();
+    // assert
+    expect(sut.message).to.include(expected);
+  });
+  it('sets context as expected', () => {
+    // arrange
+    const expected = new NodeDataErrorContextStub();
+    // act
+    const sut = new NodeDataErrorBuilder()
+      .withContext(expected)
+      .build();
+    // assert
+    expect(sut.context).to.equal(expected);
+  });
+  it('sets stack as expected', () => {
+    // arrange
+    // act
+    const sut = new NodeDataErrorBuilder()
+      .build();
+    // assert
+    expect(sut.stack !== undefined);
+  });
+  it('extends Error', () => {
+    // arrange
+    const expected = Error;
+    // act
+    const sut = new NodeDataErrorBuilder().build();
+    // assert
+    expect(sut).to.be.an.instanceof(expected);
+  });
+});
+
+class NodeDataErrorBuilder {
+  private message = 'error';
+
+  private context: INodeDataErrorContext = new NodeDataErrorContextStub();
+
+  public withContext(context: INodeDataErrorContext) {
+    this.context = context;
+    return this;
+  }
+
+  public withMessage(message: string) {
+    this.message = message;
+    return this;
+  }
+
+  public build(): NodeDataError {
+    return new NodeDataError(this.message, this.context);
+  }
+}

tests/unit/application/Parser/NodeValidation/NodeValidator.spec.ts

@@ -0,0 +1,100 @@
+import 'mocha';
+import { expect } from 'chai';
+import { NodeDataError } from '@/application/Parser/NodeValidation/NodeDataError';
+import { NodeValidator } from '@/application/Parser/NodeValidation/NodeValidator';
+import { expectThrowsError } from '@tests/unit/shared/Assertions/ExpectThrowsError';
+import { CategoryDataStub } from '@tests/unit/shared/Stubs/CategoryDataStub';
+import { NodeDataErrorContextStub } from '@tests/unit/shared/Stubs/NodeDataErrorContextStub';
+import { NodeData } from '@/application/Parser/NodeValidation/NodeData';
+import { NodeValidationTestRunner } from './NodeValidatorTestRunner';
+
+describe('NodeValidator', () => {
+  describe('assertValidName', () => {
+    describe('throws if invalid', () => {
+      // arrange
+      const context = new NodeDataErrorContextStub();
+      const sut = new NodeValidator(context);
+      // act
+      const act = (invalidName: string) => sut.assertValidName(invalidName);
+      // assert
+      new NodeValidationTestRunner()
+        .testInvalidNodeName((invalidName) => ({
+          act: () => act(invalidName),
+          expectedContext: context,
+        }));
+    });
+    it('does not throw if valid', () => {
+      // arrange
+      const validName = 'validName';
+      const sut = new NodeValidator(new NodeDataErrorContextStub());
+      // act
+      const act = () => sut.assertValidName(validName);
+      // assert
+      expect(act).to.not.throw();
+    });
+  });
+  describe('assertDefined', () => {
+    describe('throws if missing', () => {
+      // arrange
+      const context = new NodeDataErrorContextStub();
+      const sut = new NodeValidator(context);
+      // act
+      const act = (undefinedNode: NodeData) => sut.assertDefined(undefinedNode);
+      // assert
+      new NodeValidationTestRunner()
+        .testMissingNodeData((invalidName) => ({
+          act: () => act(invalidName),
+          expectedContext: context,
+        }));
+    });
+    it('does not throw if defined', () => {
+      // arrange
+      const definedNode = mockNode();
+      const sut = new NodeValidator(new NodeDataErrorContextStub());
+      // act
+      const act = () => sut.assertDefined(definedNode);
+      // assert
+      expect(act).to.not.throw();
+    });
+  });
+  describe('assert', () => {
+    it('throws expected error if condition is false', () => {
+      // arrange
+      const message = 'error';
+      const falsePredicate = () => false;
+      const context = new NodeDataErrorContextStub();
+      const expected = new NodeDataError(message, context);
+      const sut = new NodeValidator(context);
+      // act
+      const act = () => sut.assert(falsePredicate, message);
+      // assert
+      expectThrowsError(act, expected);
+    });
+    it('does not throw if condition is true', () => {
+      // arrange
+      const truePredicate = () => true;
+      const sut = new NodeValidator(new NodeDataErrorContextStub());
+      // act
+      const act = () => sut.assert(truePredicate, 'ignored error');
+      // assert
+      expect(act).to.not.throw();
+    });
+  });
+  describe('throw', () => {
+    it('throws expected error', () => {
+      // arrange
+      const message = 'error';
+      const context = new NodeDataErrorContextStub();
+      const expected = new NodeDataError(message, context);
+      const sut = new NodeValidator(context);
+      // act
+      const act = () => sut.throw(message);
+      // assert
+      expectThrowsError(act, expected);
+    });
+  });
+});
+
+function mockNode() {
+  return new CategoryDataStub();
+}

tests/unit/application/Parser/NodeValidation/NodeValidatorTestRunner.ts

@@ -0,0 +1,87 @@
+import 'mocha';
+import { NodeDataError, INodeDataErrorContext } from '@/application/Parser/NodeValidation/NodeDataError';
+import { NodeData } from '@/application/Parser/NodeValidation/NodeData';
+import { AbsentObjectTestCases, AbsentStringTestCases, itEachAbsentTestCase } from '@tests/unit/shared/TestCases/AbsentTests';
+import { expectThrowsError } from '@tests/unit/shared/Assertions/ExpectThrowsError';
+
+export interface ITestScenario {
+  readonly act: () => void;
+  readonly expectedContext: INodeDataErrorContext;
+}
+
+export class NodeValidationTestRunner {
+  public testInvalidNodeName(
+    testBuildPredicate: (invalidName: string) => ITestScenario,
+  ) {
+    describe('throws given invalid names', () => {
+      // arrange
+      const testCases = [
+        ...AbsentStringTestCases.map((testCase) => ({
+          testName: `missing name (${testCase.valueName})`,
+          nameValue: testCase.absentValue,
+          expectedMessage: 'missing name',
+        })),
+        {
+          testName: 'invalid type',
+          nameValue: 33,
+          expectedMessage: 'Name (33) is not a string but number.',
+        },
+      ];
+      for (const testCase of testCases) {
+        it(`given "${testCase.testName}"`, () => {
+          const test = testBuildPredicate(testCase.nameValue as never);
+          expectThrowsNodeError(test, testCase.expectedMessage);
+        });
+      }
+    });
+    return this;
+  }
+
+  public testMissingNodeData(
+    testBuildPredicate: (missingNode: NodeData) => ITestScenario,
+  ) {
+    describe('throws given missing node data', () => {
+      itEachAbsentTestCase([
+        ...AbsentObjectTestCases,
+        {
+          valueName: 'empty object',
+          absentValue: {},
+        },
+      ], (absentValue) => {
+        // arrange
+        const expectedError = 'missing node data';
+        // act
+        const test = testBuildPredicate(absentValue as NodeData);
+        // assert
+        expectThrowsNodeError(test, expectedError);
+      });
+    });
+    return this;
+  }
+
+  public runThrowingCase(
+    testCase: {
+      readonly name: string,
+      readonly scenario: ITestScenario,
+      readonly expectedMessage: string
+    },
+  ) {
+    it(testCase.name, () => {
+      expectThrowsNodeError(testCase.scenario, testCase.expectedMessage);
+    });
+    return this;
+  }
+}
+
+export function expectThrowsNodeError(
+  test: ITestScenario,
+  expectedMessage: string,
+) {
+  // arrange
+  const expected = new NodeDataError(expectedMessage, test.expectedContext);
+  // act
+  const act = () => test.act();
+  // assert
+  expectThrowsError(act, expected);
+  return this;
+}

tests/unit/application/Parser/Script/ScriptParser.spec.ts

@@ -1,16 +1,21 @@
 import 'mocha';
 import { expect } from 'chai';
-import { parseScript } from '@/application/Parser/Script/ScriptParser';
+import type { ScriptData } from '@/application/collections/';
+import { parseScript, ScriptFactoryType } from '@/application/Parser/Script/ScriptParser';
 import { parseDocUrls } from '@/application/Parser/DocumentationParser';
 import { RecommendationLevel } from '@/domain/RecommendationLevel';
 import { ICategoryCollectionParseContext } from '@/application/Parser/Script/ICategoryCollectionParseContext';
+import { itEachAbsentObjectValue, itEachAbsentStringValue } from '@tests/unit/shared/TestCases/AbsentTests';
 import { ScriptCompilerStub } from '@tests/unit/shared/Stubs/ScriptCompilerStub';
 import { ScriptDataStub } from '@tests/unit/shared/Stubs/ScriptDataStub';
 import { EnumParserStub } from '@tests/unit/shared/Stubs/EnumParserStub';
 import { ScriptCodeStub } from '@tests/unit/shared/Stubs/ScriptCodeStub';
 import { CategoryCollectionParseContextStub } from '@tests/unit/shared/Stubs/CategoryCollectionParseContextStub';
 import { LanguageSyntaxStub } from '@tests/unit/shared/Stubs/LanguageSyntaxStub';
-import { itEachAbsentObjectValue, itEachAbsentStringValue } from '@tests/unit/shared/TestCases/AbsentTests';
+import { NodeType } from '@/application/Parser/NodeValidation/NodeType';
+import { expectThrowsNodeError, ITestScenario, NodeValidationTestRunner } from '@tests/unit/application/Parser/NodeValidation/NodeValidatorTestRunner';
+import { Script } from '@/domain/Script';
+import { IEnumParser } from '@/application/Common/Enum';
 
 describe('ScriptParser', () => {
   describe('parseScript', () => {
@@ -19,9 +24,10 @@ describe('ScriptParser', () => {
       const expected = 'test-expected-name';
       const script = ScriptDataStub.createWithCode()
         .withName(expected);
-      const parseContext = new CategoryCollectionParseContextStub();
       // act
-      const actual = parseScript(script, parseContext);
+      const actual = new TestBuilder()
+        .withData(script)
+        .parseScript();
       // assert
       expect(actual.name).to.equal(expected);
     });
@@ -30,86 +36,42 @@ describe('ScriptParser', () => {
       const docs = ['https://expected-doc1.com', 'https://expected-doc2.com'];
       const script = ScriptDataStub.createWithCode()
         .withDocs(docs);
-      const parseContext = new CategoryCollectionParseContextStub();
       const expected = parseDocUrls(script);
       // act
-      const actual = parseScript(script, parseContext);
+      const actual = new TestBuilder()
+        .withData(script)
+        .parseScript();
       // assert
       expect(actual.documentationUrls).to.deep.equal(expected);
     });
-    describe('invalid script', () => {
-      describe('throws when script is absent', () => {
-        itEachAbsentObjectValue((absentValue) => {
-          // arrange
-          const expectedError = 'missing script';
-          const parseContext = new CategoryCollectionParseContextStub();
-          const script = absentValue;
-          // act
-          const act = () => parseScript(script, parseContext);
-          // assert
-          expect(act).to.throw(expectedError);
-        });
-      });
-      it('throws when both function call and code are defined', () => {
-        // arrange
-        const expectedError = 'cannot define both "call" and "code"';
-        const parseContext = new CategoryCollectionParseContextStub();
-        const script = ScriptDataStub
-          .createWithCall()
-          .withCode('code');
-        // act
-        const act = () => parseScript(script, parseContext);
-        // assert
-        expect(act).to.throw(expectedError);
-      });
-      it('throws when both function call and revertCode are defined', () => {
-        // arrange
-        const expectedError = 'cannot define "revertCode" if "call" is defined';
-        const parseContext = new CategoryCollectionParseContextStub();
-        const script = ScriptDataStub
-          .createWithCall()
-          .withRevertCode('revert-code');
-        // act
-        const act = () => parseScript(script, parseContext);
-        // assert
-        expect(act).to.throw(expectedError);
-      });
-      it('throws when neither call or revertCode are defined', () => {
-        // arrange
-        const expectedError = 'must define either "call" or "code"';
-        const parseContext = new CategoryCollectionParseContextStub();
-        const script = ScriptDataStub.createWithoutCallOrCodes();
-        // act
-        const act = () => parseScript(script, parseContext);
-        // assert
-        expect(act).to.throw(expectedError);
-      });
-    });
     describe('level', () => {
       describe('accepts absent level', () => {
         itEachAbsentStringValue((absentValue) => {
           // arrange
-          const parseContext = new CategoryCollectionParseContextStub();
           const script = ScriptDataStub.createWithCode()
             .withRecommend(absentValue);
           // act
-          const actual = parseScript(script, parseContext);
+          const actual = new TestBuilder()
+            .withData(script)
+            .parseScript();
           // assert
           expect(actual.level).to.equal(undefined);
         });
       });
-      describe('parses level as expected', () => {
+      it('parses level as expected', () => {
         // arrange
         const expectedLevel = RecommendationLevel.Standard;
         const expectedName = 'level';
         const levelText = 'standard';
         const script = ScriptDataStub.createWithCode()
           .withRecommend(levelText);
-        const parseContext = new CategoryCollectionParseContextStub();
         const parserMock = new EnumParserStub<RecommendationLevel>()
           .setup(expectedName, levelText, expectedLevel);
         // act
-        const actual = parseScript(script, parseContext, parserMock);
+        const actual = new TestBuilder()
+          .withData(script)
+          .withParser(parserMock)
+          .parseScript();
         // assert
         expect(actual.level).to.equal(expectedLevel);
       });
@@ -121,9 +83,10 @@ describe('ScriptParser', () => {
         const script = ScriptDataStub
           .createWithCode()
           .withCode(expected);
-        const parseContext = new CategoryCollectionParseContextStub();
         // act
-        const parsed = parseScript(script, parseContext);
+        const parsed = new TestBuilder()
+          .withData(script)
+          .parseScript();
         // assert
         const actual = parsed.code.execute;
         expect(actual).to.equal(expected);
@@ -134,9 +97,10 @@ describe('ScriptParser', () => {
         const script = ScriptDataStub
           .createWithCode()
           .withRevertCode(expected);
-        const parseContext = new CategoryCollectionParseContextStub();
         // act
-        const parsed = parseScript(script, parseContext);
+        const parsed = new TestBuilder()
+          .withData(script)
+          .parseScript();
         // assert
         const actual = parsed.code.revert;
         expect(actual).to.equal(expected);
@@ -146,10 +110,11 @@ describe('ScriptParser', () => {
           itEachAbsentObjectValue((absentValue) => {
             // arrange
             const expectedMessage = 'missing context';
-            const script = ScriptDataStub.createWithCode();
             const context: ICategoryCollectionParseContext = absentValue;
             // act
-            const act = () => parseScript(script, context);
+            const act = () => new TestBuilder()
+              .withContext(context)
+              .parseScript();
             // assert
             expect(act).to.throw(expectedMessage);
           });
@@ -163,14 +128,17 @@ describe('ScriptParser', () => {
           const parseContext = new CategoryCollectionParseContextStub()
             .withCompiler(compiler);
           // act
-          const parsed = parseScript(script, parseContext);
+          const parsed = new TestBuilder()
+            .withData(script)
+            .withContext(parseContext)
+            .parseScript();
           // assert
           const actual = parsed.code;
           expect(actual).to.equal(expected);
         });
       });
       describe('syntax', () => {
-        it('set from the context', () => { // test through script validation logic
+        it('set from the context', () => { // tests through script validation logic
           // arrange
           const commentDelimiter = 'should not throw';
           const duplicatedCode = `${commentDelimiter} duplicate-line\n${commentDelimiter} duplicate-line`;
@@ -180,11 +148,112 @@ describe('ScriptParser', () => {
             .createWithoutCallOrCodes()
             .withCode(duplicatedCode);
           // act
-          const act = () => parseScript(script, parseContext);
+          const act = () => new TestBuilder()
+            .withData(script)
+            .withContext(parseContext);
           // assert
           expect(act).to.not.throw();
         });
       });
     });
+    describe('invalid script data', () => {
+      describe('validates script data', () => {
+        // arrange
+        const createTest = (script: ScriptData): ITestScenario => ({
+          act: () => new TestBuilder()
+            .withData(script)
+            .parseScript(),
+          expectedContext: {
+            type: NodeType.Script,
+            selfNode: script,
+          },
+        });
+        // act and assert
+        new NodeValidationTestRunner()
+          .testInvalidNodeName((invalidName) => {
+            return createTest(
+              ScriptDataStub.createWithCall().withName(invalidName),
+            );
+          })
+          .testMissingNodeData((node) => {
+            return createTest(node as ScriptData);
+          })
+          .runThrowingCase({
+            name: 'throws when both function call and code are defined',
+            scenario: createTest(
+              ScriptDataStub.createWithCall().withCode('code'),
+            ),
+            expectedMessage: 'Cannot define both "call" and "code".',
+          })
+          .runThrowingCase({
+            name: 'throws when both function call and revertCode are defined',
+            scenario: createTest(
+              ScriptDataStub.createWithCall().withRevertCode('revert-code'),
+            ),
+            expectedMessage: 'Cannot define "revertCode" if "call" is defined.',
+          })
+          .runThrowingCase({
+            name: 'throws when neither call or revertCode are defined',
+            scenario: createTest(
+              ScriptDataStub.createWithoutCallOrCodes(),
+            ),
+            expectedMessage: 'Must define either "call" or "code".',
+          });
+      });
+      it(`rethrows exception if ${Script.name} cannot be constructed`, () => {
+        // arrange
+        const expectedError = 'script creation failed';
+        const factoryMock: ScriptFactoryType = () => { throw new Error(expectedError); };
+        const data = ScriptDataStub.createWithCode();
+        // act
+        const act = () => new TestBuilder()
+          .withData(data)
+          .withFactory(factoryMock)
+          .parseScript();
+        // expect
+        expectThrowsNodeError({
+          act,
+          expectedContext: {
+            type: NodeType.Script,
+            selfNode: data,
+          },
+        }, expectedError);
+      });
+    });
   });
 });
+
+class TestBuilder {
+  private data: ScriptData = ScriptDataStub.createWithCode();
+
+  private context: ICategoryCollectionParseContext = new CategoryCollectionParseContextStub();
+
+  private parser: IEnumParser<RecommendationLevel> = new EnumParserStub<RecommendationLevel>()
+    .setupDefaultValue(RecommendationLevel.Standard);
+
+  private factory: ScriptFactoryType = undefined;
+
+  public withData(data: ScriptData) {
+    this.data = data;
+    return this;
+  }
+
+  public withContext(context: ICategoryCollectionParseContext) {
+    this.context = context;
+    return this;
+  }
+
+  public withParser(parser: IEnumParser<RecommendationLevel>) {
+    this.parser = parser;
+    return this;
+  }
+
+  public withFactory(factory: ScriptFactoryType) {
+    this.factory = factory;
+    return this;
+  }
+
+  public parseScript(): Script {
+    return parseScript(this.data, this.context, this.parser, this.factory);
+  }
+}