Improve compiler output for line validation

This commit improves feedback when a line is too long to enhance
developer/maintainer productivity.

- Trim long lines in output to 500 characters
- Show character count exceeding max line length
- Refactor line formatting for better readability

src/application/Parser/Executable/Script/Validation/Analyzers/AnalyzeTooLongLines.ts

@@ -12,7 +12,7 @@ export const analyzeTooLongLines: CodeValidationAnalyzer = (
       lineNumber: line.lineNumber,
       error: [
         `Line is too long (${line.text.length}).`,
-        `It exceed maximum allowed length ${maxLineLength}.`,
+        `It exceed maximum allowed length ${maxLineLength} by ${line.text.length - maxLineLength} characters.`,
         'This may cause bugs due to unintended trimming by operating system, shells or terminal emulators.',
       ].join(' '),
     }));
@@ -39,6 +39,6 @@ function getMaxAllowedLineLength(language: ScriptingLanguage): number {
       */
       return 1048576; // Minimum value for reliability
     default:
-      throw new Error(`Unsupported language: ${language}`);
+      throw new Error(`Unsupported language: ${ScriptingLanguage[language]} (${language})`);
   }
 }

src/application/Parser/Executable/Script/Validation/CodeValidator.ts

@@ -46,9 +46,33 @@ function formatLines(
 ): string {
   return lines.map((line) => {
     const badLine = invalidLines.find((invalidLine) => invalidLine.lineNumber === line.lineNumber);
-    if (!badLine) {
-      return `[${line.lineNumber}] ✅ ${line.text}`;
-    }
-    return `[${badLine.lineNumber}] ❌ ${line.text}\n\t⟶ ${badLine.error}`;
+    return formatLine({
+      lineNumber: line.lineNumber,
+      text: line.text,
+      error: badLine?.error,
+    });
   }).join('\n');
 }
+function formatLine(
+  line: {
+    readonly lineNumber: number;
+    readonly text: string;
+    readonly error?: string;
+  },
+): string {
+  let text = `[${line.lineNumber}] `;
+  text += line.error ? '❌' : '✅';
+  text += ` ${trimLine(line.text)}`;
+  if (line.error) {
+    text += `\n\t⟶ ${line.error}`;
+  }
+  return text;
+}
+
+function trimLine(line: string) {
+  const maxLength = 500;
+  if (line.length > maxLength) {
+    line = `${line.substring(0, maxLength)}... [Rest of the line trimmed]`;
+  }
+  return line;
+}

tests/unit/application/Parser/Executable/Script/Validation/Analyzers/AnalyzeTooLongLines.spec.ts

@@ -3,161 +3,173 @@ import type { CodeLine, InvalidCodeLine } from '@/application/Parser/Executable/
 import { ScriptingLanguage } from '@/domain/ScriptingLanguage';
 import { analyzeTooLongLines } from '@/application/Parser/Executable/Script/Validation/Analyzers/AnalyzeTooLongLines';
 import { createCodeLines } from './CreateCodeLines';
-import { expectSameInvalidCodeLines } from './ExpectSameInvalidCodeLines';
+import { expectInvalidCodeLines, expectSameInvalidCodeLines } from './ExpectSameInvalidCodeLines';
 
 describe('AnalyzeTooLongLines', () => {
   describe('analyzeTooLongLines', () => {
-    describe('batchfile', () => {
-      const MAX_BATCHFILE_LENGTH = 8191;
-
-      it('returns no results for lines within the maximum length', () => {
-        // arrange
-        const expected: InvalidCodeLine[] = [];
-        const context = new TestContext()
-          .withLanguage(ScriptingLanguage.batchfile)
-          .withLines([
-            'A'.repeat(MAX_BATCHFILE_LENGTH),
-            'B'.repeat(8000),
-            'C'.repeat(100),
-          ]);
-        // act
-        const actual = context.analyze();
-        // assert
-        expectSameInvalidCodeLines(actual, expected);
+    describe('returns no results for lines within the maximum length', () => {
+      createScriptLanguageScenarios().forEach((scenario) => {
+        it(scenario.description, () => {
+          // arrange
+          const expected: InvalidCodeLine[] = [];
+          const context = new TestContext()
+            .withLanguage(scenario.language)
+            .withLines([
+              'A'.repeat(scenario.maxLength),
+              'B'.repeat(scenario.maxLength - 1),
+              'C'.repeat(100),
+            ]);
+          // act
+          const actual = context.analyze();
+          // assert
+          expectSameInvalidCodeLines(actual, expected);
+        });
       });
+    });
 
-      it('identifies a single line exceeding maximum length', () => {
-        // arrange
-        const expectedLength = MAX_BATCHFILE_LENGTH + 1;
-        const expected: InvalidCodeLine[] = [{
-          lineNumber: 2,
-          error: createTooLongLineError(expectedLength, MAX_BATCHFILE_LENGTH),
-        }];
-        const context = new TestContext()
-          .withLanguage(ScriptingLanguage.batchfile)
-          .withLines([
-            'A'.repeat(MAX_BATCHFILE_LENGTH),
-            'B'.repeat(expectedLength),
-            'C'.repeat(100),
-          ]);
-        // act
-        const actual = context.analyze();
-        // assert
-        expectSameInvalidCodeLines(actual, expected);
+    describe('identifies a single line exceeding maximum length', () => {
+      createScriptLanguageScenarios().forEach((scenario) => {
+        it(scenario.description, () => {
+          // arrange
+          const expectedLength = scenario.maxLength + 1;
+          const expectedLineNumber = 2;
+          const context = new TestContext()
+            .withLanguage(scenario.language)
+            .withLines([
+              'A'.repeat(scenario.maxLength),
+              'B'.repeat(expectedLength),
+              'C'.repeat(100),
+            ]);
+          // act
+          const actual = context.analyze();
+          // assert
+          expectInvalidCodeLines(actual, [expectedLineNumber]);
+        });
       });
+    });
 
-      it('identifies multiple lines exceeding maximum length', () => {
-        // arrange
-        const expectedLength1 = MAX_BATCHFILE_LENGTH + 1;
-        const expectedLength2 = MAX_BATCHFILE_LENGTH + 2;
-        const expected: InvalidCodeLine[] = [
-          {
-            lineNumber: 1,
-            error: createTooLongLineError(expectedLength1, MAX_BATCHFILE_LENGTH),
-          },
-          {
-            lineNumber: 3,
-            error: createTooLongLineError(expectedLength2, MAX_BATCHFILE_LENGTH),
-          },
-        ];
-        const context = new TestContext()
-          .withLanguage(ScriptingLanguage.batchfile)
-          .withLines([
-            'A'.repeat(expectedLength1),
-            'B'.repeat(MAX_BATCHFILE_LENGTH),
-            'C'.repeat(expectedLength2),
-          ]);
-        // act
-        const actual = context.analyze();
-        // assert
-        expectSameInvalidCodeLines(actual, expected);
+    describe('identifies multiple lines exceeding maximum length', () => {
+      createScriptLanguageScenarios().forEach((scenario) => {
+        it(scenario.description, () => {
+          // arrange
+          const expectedInvalidLines: readonly {
+            readonly lineNumber: number,
+            readonly length: number,
+          }[] = [
+            { lineNumber: 1, length: scenario.maxLength + 1 },
+            { lineNumber: 3, length: scenario.maxLength + 2 },
+          ];
+          const context = new TestContext()
+            .withLanguage(scenario.language)
+            .withLines([
+              'A'.repeat(expectedInvalidLines[0].length),
+              'B'.repeat(scenario.maxLength),
+              'C'.repeat(expectedInvalidLines[1].length),
+            ]);
+          // act
+          const actual = context.analyze();
+          // assert
+          expectInvalidCodeLines(actual, expectedInvalidLines.map((l) => l.lineNumber));
+        });
       });
     });
 
-    describe('shellscript', () => {
-      const MAX_SHELLSCRIPT_LENGTH = 1048576;
-
-      it('returns no results for lines within the maximum length', () => {
-        // arrange
-        const expected: InvalidCodeLine[] = [];
-        const context = new TestContext()
-          .withLanguage(ScriptingLanguage.shellscript)
-          .withLines([
-            'A'.repeat(MAX_SHELLSCRIPT_LENGTH),
-            'B'.repeat(1000000),
-            'C'.repeat(100),
-          ]);
-        // act
-        const actual = context.analyze();
-        // assert
-        expectSameInvalidCodeLines(actual, expected);
+    describe('error construction', () => {
+      describe('outputs actual character length', () => {
+        createScriptLanguageScenarios().forEach((scenario) => {
+          it(scenario.description, () => {
+            // arrange
+            const expectedLength = scenario.maxLength + 1;
+            const expectedErrorPart = `Line is too long (${expectedLength}).`;
+            const context = new TestContext()
+              .withLanguage(scenario.language)
+              .withLines([
+                'B'.repeat(expectedLength),
+              ]);
+            // act
+            const actual = context.analyze();
+            // assert
+            expect(actual).to.have.lengthOf(1);
+            const actualError = actual[0].error;
+            expect(actualError).to.include(expectedErrorPart);
+          });
+        });
       });
-
-      it('identifies a single line exceeding maximum length', () => {
-        // arrange
-        const expectedLength = MAX_SHELLSCRIPT_LENGTH + 1;
-        const expected: InvalidCodeLine[] = [{
-          lineNumber: 2,
-          error: createTooLongLineError(expectedLength, MAX_SHELLSCRIPT_LENGTH),
-        }];
-        const context = new TestContext()
-          .withLanguage(ScriptingLanguage.shellscript)
-          .withLines([
-            'A'.repeat(MAX_SHELLSCRIPT_LENGTH),
-            'B'.repeat(expectedLength),
-            'C'.repeat(100),
-          ]);
-        // act
-        const actual = context.analyze();
-        // assert
-        expectSameInvalidCodeLines(actual, expected);
+      describe('outputs maximum allowed character length', () => {
+        createScriptLanguageScenarios().forEach((scenario) => {
+          it(scenario.description, () => {
+            // arrange
+            const expectedLength = scenario.maxLength + 1;
+            const expectedErrorPart = `It exceed maximum allowed length ${scenario.maxLength}`;
+            const context = new TestContext()
+              .withLanguage(scenario.language)
+              .withLines([
+                'B'.repeat(expectedLength),
+              ]);
+            // act
+            const actual = context.analyze();
+            // assert
+            expect(actual).to.have.lengthOf(1);
+            const actualError = actual[0].error;
+            expect(actualError).to.include(expectedErrorPart);
+          });
+        });
       });
-
-      it('identifies multiple lines exceeding maximum length', () => {
-        // arrange
-        const expectedLength1 = MAX_SHELLSCRIPT_LENGTH + 1;
-        const expectedLength2 = MAX_SHELLSCRIPT_LENGTH + 2;
-        const expected: InvalidCodeLine[] = [
-          {
-            lineNumber: 1,
-            error: createTooLongLineError(expectedLength1, MAX_SHELLSCRIPT_LENGTH),
-          },
-          {
-            lineNumber: 3,
-            error: createTooLongLineError(expectedLength2, MAX_SHELLSCRIPT_LENGTH),
-          },
-        ];
-        const context = new TestContext()
-          .withLanguage(ScriptingLanguage.shellscript)
-          .withLines([
-            'A'.repeat(expectedLength1),
-            'B'.repeat(MAX_SHELLSCRIPT_LENGTH),
-            'C'.repeat(expectedLength2),
-          ]);
-        // act
-        const actual = context.analyze();
-        // assert
-        expectSameInvalidCodeLines(actual, expected);
+      describe('outputs total exceeding characters', () => {
+        createScriptLanguageScenarios().forEach((scenario) => {
+          it(scenario.description, () => {
+            // arrange
+            const expectedExceedingCharacters = 5;
+            const expectedErrorPart = `by ${expectedExceedingCharacters} characters.`;
+            const lineLength = scenario.maxLength + expectedExceedingCharacters;
+            const context = new TestContext()
+              .withLanguage(scenario.language)
+              .withLines([
+                'B'.repeat(lineLength),
+              ]);
+            // act
+            const actual = context.analyze();
+            // assert
+            expect(actual).to.have.lengthOf(1);
+            const actualError = actual[0].error;
+            expect(actualError).to.include(expectedErrorPart);
+          });
+        });
       });
     });
 
     it('throws an error for unsupported language', () => {
       // arrange
+      const unsupportedLanguage = 'unsupported' as unknown as ScriptingLanguage;
+      const expectedError = `Unsupported language: ${ScriptingLanguage[unsupportedLanguage]} (${unsupportedLanguage})`;
       const context = new TestContext()
         .withLanguage('unsupported' as unknown as ScriptingLanguage)
         .withLines(['A', 'B', 'C']);
-      // act & assert
-      expect(() => context.analyze()).to.throw('Unsupported language: unsupported');
+      // act
+      const act = () => context.analyze();
+      // assert
+      expect(act).to.throw(expectedError);
     });
   });
 });
 
-function createTooLongLineError(actualLength: number, maxAllowedLength: number): string {
-  return [
-    `Line is too long (${actualLength}).`,
-    `It exceed maximum allowed length ${maxAllowedLength}.`,
-    'This may cause bugs due to unintended trimming by operating system, shells or terminal emulators.',
-  ].join(' ');
+interface ScriptLanguageScenario {
+  readonly description: string;
+  readonly maxLength: number;
+  readonly language: ScriptingLanguage;
+}
+
+function createScriptLanguageScenarios(): readonly ScriptLanguageScenario[] {
+  const maxLengths: Record< // `Record` catches missing entries at compile-time
+  ScriptingLanguage, number> = {
+    [ScriptingLanguage.batchfile]: 8191,
+    [ScriptingLanguage.shellscript]: 1048576,
+  };
+  return Object.entries(maxLengths).map(([language, length]): ScriptLanguageScenario => ({
+    description: `${ScriptingLanguage[language]} (max: ${length})`,
+    language: Number.parseInt(language, 10) as ScriptingLanguage,
+    maxLength: length,
+  }));
 }
 
 class TestContext {

tests/unit/application/Parser/Executable/Script/Validation/Analyzers/ExpectSameInvalidCodeLines.ts

@@ -1,11 +1,32 @@
 import { expect } from 'vitest';
 import type { InvalidCodeLine } from '@/application/Parser/Executable/Script/Validation/Analyzers/CodeValidationAnalyzer';
+import { formatAssertionMessage } from '@tests/shared/FormatAssertionMessage';
 
 export function expectSameInvalidCodeLines(
   expected: readonly InvalidCodeLine[],
   actual: readonly InvalidCodeLine[],
 ) {
-  expect(sort(expected)).to.deep.equal(sort(actual));
+  const sortedExpected = sort(expected);
+  const sortedActual = sort(actual);
+
+  expect(sortedActual).to.deep.equal(sortedExpected, formatAssertionMessage([
+    'Invalid code lines do not match',
+    `Expected: ${JSON.stringify(sortedExpected, null, 2)}`,
+    `Actual: ${JSON.stringify(sortedActual, null, 2)}`,
+  ]));
+}
+
+export function expectInvalidCodeLines(
+  actual: readonly InvalidCodeLine[],
+  expectedInvalidLineNumbers: readonly number[],
+) {
+  const sortedActualLineNumbers = actual.map((a) => a.lineNumber).sort();
+  const sortedExpectedLineNumbers = [...expectedInvalidLineNumbers].sort();
+  expect(sortedActualLineNumbers).to.deep.equal(sortedExpectedLineNumbers, formatAssertionMessage([
+    'Invalid line numbers do not match.',
+    `Expected (${sortedExpectedLineNumbers.length}): ${sortedExpectedLineNumbers.join(', ')}`,
+    `Actual (${sortedActualLineNumbers.length}): ${sortedActualLineNumbers.join(', ')}`,
+  ]));
 }
 
 function sort(lines: readonly InvalidCodeLine[]) { // To ignore order