chore(jsii): better errors around use of hidden types

packages/jsii/test/negatives.test.ts

@@ -6,6 +6,12 @@ import { ProjectInfo } from '../lib/project-info';
 
 const SOURCE_DIR = path.join(__dirname, 'negatives');
 
+const formatHost: ts.FormatDiagnosticsHost = {
+  getCanonicalFileName: ts.sys.realpath ?? ts.sys.resolvePath,
+  getCurrentDirectory: () => SOURCE_DIR,
+  getNewLine: () => '\n',
+};
+
 for (const source of fs.readdirSync(SOURCE_DIR)) {
   if (
     !source.startsWith('neg.') ||
@@ -18,30 +24,33 @@ for (const source of fs.readdirSync(SOURCE_DIR)) {
   test(
     source.replace(/neg\.(.+)\.ts/, '$1'),
     async () => {
-      const [expectations, strict] = await _getExpectedErrorMessage(filePath);
-      expect(
-        expectations.length,
-        `Expected error messages should be specified using ${MATCH_ERROR_MARKER}`,
-      ).toBeGreaterThan(0);
+      const { strict } = await _getPragmas(filePath);
       const compiler = new Compiler({
         projectInfo: _makeProjectInfo(source),
         failOnWarnings: strict,
       });
       const emitResult = await compiler.emit(path.join(SOURCE_DIR, source));
+
       expect(emitResult.emitSkipped).toBeTruthy();
-      const errors = emitResult.diagnostics.filter(
-        (diag) =>
-          diag.category === ts.DiagnosticCategory.Error ||
-          (strict && diag.category === ts.DiagnosticCategory.Warning),
-      );
-      for (const expectation of expectations) {
-        expect(
-          errors.find((e) => _messageText(e).includes(expectation)),
-          `No error contained: ${expectation}. Errors: \n${errors
-            .map((e, i) => `[${i}] ${e.messageText.toString()}`)
-            .join('\n')}`,
-        ).toBeDefined();
-      }
+
+      const diagnostics = emitResult.diagnostics
+        .filter(
+          // Remove suggestion diagnostics, we don't care much for those for now...
+          (diag) => diag.category !== ts.DiagnosticCategory.Suggestion,
+        )
+        .map((diag) =>
+          ts.formatDiagnosticsWithColorAndContext([diag], formatHost),
+        )
+        .sort();
+
+      expect(diagnostics.length).toBeGreaterThan(0);
+      expect(
+        diagnostics
+          // Remove ANSI color codes from the message so it's nicer in the snapshots file
+          // eslint-disable-next-line no-control-regex
+          .map((diag) => diag.replace(/\x1B\[[0-9;]*[a-z]/gi, ''))
+          .join(''),
+      ).toMatchSnapshot();
 
       // Cleaning up...
       return Promise.all(
@@ -65,32 +74,12 @@ for (const source of fs.readdirSync(SOURCE_DIR)) {
   );
 }
 
-const MATCH_ERROR_MARKER = '///!MATCH_ERROR:';
 const STRICT_MARKER = '///!STRICT!';
-async function _getExpectedErrorMessage(
-  file: string,
-): Promise<[string[], boolean]> {
+async function _getPragmas(file: string): Promise<{ strict: boolean }> {
   const data = await fs.readFile(file, { encoding: 'utf8' });
   const lines = data.split('\n');
-  const matches = lines
-    .filter((line) => line.startsWith(MATCH_ERROR_MARKER))
-    .map((line) => line.substr(MATCH_ERROR_MARKER.length).trim());
   const strict = lines.some((line) => line.startsWith(STRICT_MARKER));
-  return [matches, strict];
-}
-
-function _messageText(
-  diagnostic: ts.Diagnostic | ts.DiagnosticMessageChain,
-): string {
-  if (typeof diagnostic.messageText === 'string') {
-    return diagnostic.messageText;
-  }
-  if (diagnostic.messageText.next) {
-    return `${diagnostic.messageText.messageText}|${_messageText(
-      diagnostic.messageText.next[0],
-    )}`;
-  }
-  return diagnostic.messageText.messageText;
+  return { strict };
 }
 
 function _makeProjectInfo(types: string): ProjectInfo {

packages/jsii/test/negatives/neg.behavior-requires-iprefix.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: Interface contains behavior: name should be "ISomething"
-
 export interface Something {
   // The presence of this method requires an I prefix on the interface
   doSomething(): void;

packages/jsii/test/negatives/neg.class-name.1.ts

@@ -1,5 +1 @@
-///!MATCH_ERROR: Type names must use PascalCase: My_class
-
-export class My_class {
-
-}
+export class My_class {}

packages/jsii/test/negatives/neg.class-name.ts

@@ -1,5 +1 @@
-///!MATCH_ERROR: Type names must use PascalCase: myclass
-
-export class myclass {
-
-}
+export class myclass {}

packages/jsii/test/negatives/neg.compilation-error.ts

@@ -1,4 +1 @@
-///!MATCH_ERROR: Cannot find name 'boom'.
-///!MATCH_ERROR: Cannot find name 'CompilerErrorIsHere'.
-
-boom! >CompilerErrorIsHere
+boom! > CompilerErrorIsHere;

packages/jsii/test/negatives/neg.const-enum.ts

@@ -1,8 +1,6 @@
-///!MATCH_ERROR: Exported enum cannot be declared 'const'
-
 export const enum NotAllowed {
   ThisEnum,
   GetsInlined,
   AndSoItGetsLost,
-  ForJsii
-}
+  ForJsii,
+}

packages/jsii/test/negatives/neg.double-interface-members-deeper.ts

@@ -1,15 +1,11 @@
-///!MATCH_ERROR: Interface declares same member as inherited interface: foo
-
 export interface IA {
   foo(): void;
 }
 
 export interface IB extends IA {
-    bar(): void;
+  bar(): void;
 }
 
 export interface IC extends IB {
   foo(): void;
 }
-
-

packages/jsii/test/negatives/neg.double-interface-members-method.ts

@@ -1,9 +1,6 @@
-///!MATCH_ERROR: Interface declares same member as inherited interface: foo
-
 export interface IA {
   foo(): void;
 }
 export interface IB extends IA {
   foo(): void;
 }
-

packages/jsii/test/negatives/neg.double-interface-members.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: Interface declares same member as inherited interface: foo
-
 export interface A {
   foo: number;
 }

packages/jsii/test/negatives/neg.enum-members.1.ts

@@ -1,6 +1,4 @@
-///!MATCH_ERROR: Enum members must use ALL_CAPS: Goo
-
 export enum MyEnum {
-    FOO,
-    Goo
+  FOO,
+  Goo,
 }

packages/jsii/test/negatives/neg.enum-name.1.ts

@@ -1,6 +1,4 @@
-///!MATCH_ERROR: Type names must use PascalCase: myEnum
-
 export enum myEnum {
-    FOO,
-    GOO
+  FOO,
+  GOO,
 }

packages/jsii/test/negatives/neg.enum-name.2.ts

@@ -1,6 +1,4 @@
-///!MATCH_ERROR: Type names must use PascalCase: My_Enum
-
 export enum My_Enum {
-    FOO,
-    GOO
+  FOO,
+  GOO,
 }

packages/jsii/test/negatives/neg.expose-unexported-type-external.ts

@@ -1,10 +1,8 @@
-///!MATCH_ERROR: Exported APIs cannot use un-exported type jsii.UnexportedType
-
 // Attempt to expose an unexported type defined in another file should fial
 // because that type will not be available in the module spec.
 
 import { UnexportedType } from './mylib';
 
 export class ExportedType {
-    public p?: UnexportedType;
+  public p?: UnexportedType;
 }

packages/jsii/test/negatives/neg.expose-unexported-type-internal-in-namespace.ts

@@ -1,13 +1,10 @@
-///!MATCH_ERROR: Cannot use private type MyNamespace.UnexportedType in exported declarations
-
 // Attempt to expose an unexported type defined in this file should fail
 // because that type will not be available in the module spec.
 
 namespace MyNamespace {
-    export class UnexportedType {
-    }
+  export class UnexportedType {}
 }
 
 export class ExportedType {
-    public p?: MyNamespace.UnexportedType;
+  public p?: MyNamespace.UnexportedType;
 }

packages/jsii/test/negatives/neg.expose-unexported-type-internal.ts

@@ -1,12 +1,8 @@
-///!MATCH_ERROR: Cannot use private type UnexportedType in exported declarations
-
 // Attempt to expose an unexported type defined in this file should fail
 // because that type will not be available in the module spec.
 
-class UnexportedType {
-
-}
+class UnexportedType {}
 
 export class ExportedType {
-    public p?: UnexportedType;
+  public p?: UnexportedType;
 }

packages/jsii/test/negatives/neg.expose-unexported-type-this.ts

@@ -0,0 +1,13 @@
+// Attempt to return "this" from a hidden base class
+
+abstract class HiddenBaseClass {
+  public returnsThis() {
+    return this;
+  }
+}
+
+export class PublicClass extends HiddenBaseClass {
+  public constructor(public readonly boolean = true) {
+    super();
+  }
+}

packages/jsii/test/negatives/neg.extend-struct.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: Attempted to extend struct jsii.Struct from regular interface jsii.IIllegal
-
 // Attempt to extend a Struct (aka data type) from a regular interface will fail.
 export interface Struct {
   readonly field: string;

packages/jsii/test/negatives/neg.implement-struct.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: Attempted to implement struct jsii.Struct from class jsii.Illegal
-
 // Attempt to implement a Struct (aka data type) will fail.
 export interface Struct {
   readonly field: string;

packages/jsii/test/negatives/neg.implementation-changes-types.1.ts

@@ -1,14 +1,12 @@
-///!MATCH_ERROR: jsii.Something#returnSomething changes the return type when implementing jsii.ISomething (expected jsii.Superclass, found jsii.Subclass)
-
 export class Superclass {}
 export class Subclass extends Superclass {}
 
 export interface ISomething {
-    returnSomething(): Superclass;
+  returnSomething(): Superclass;
 }
 
 export class Something implements ISomething {
-    public returnSomething(): Subclass {
-        return 5;
-    }
+  public returnSomething(): Subclass {
+    return 5;
+  }
 }

packages/jsii/test/negatives/neg.implementation-changes-types.2.ts

@@ -1,14 +1,12 @@
-///!MATCH_ERROR: jsii.ISomethingElse#returnSomething changes the return type when implementing jsii.ISomething (expected jsii.Superclass, found jsii.Subclass)
-
 export class Superclass {}
 export class Subclass extends Superclass {}
 
 export interface ISomething {
-    returnSomething(): Superclass;
+  returnSomething(): Superclass;
 }
 
 export class ISomethingElse implements ISomething {
-    public returnSomething(): Subclass {
-        return new Subclass();
-    }
+  public returnSomething(): Subclass {
+    return new Subclass();
+  }
 }

packages/jsii/test/negatives/neg.implementation-changes-types.3.ts

@@ -1,14 +1,12 @@
-///!MATCH_ERROR: jsii.Something#takeSomething changes type of argument _argument when implementing jsii.ISomething (expected jsii.Superclass, found jsii.Subclass
-
 export class Superclass {}
 export class Subclass extends Superclass {}
 
 export interface ISomething {
-    takeSomething(argument: Superclass): void;
+  takeSomething(argument: Superclass): void;
 }
 
 export class Something implements ISomething {
-    public takeSomething(_argument: Subclass): void {
-        // Nothing
-    }
+  public takeSomething(_argument: Subclass): void {
+    // Nothing
+  }
 }

packages/jsii/test/negatives/neg.implementation-changes-types.4.ts

@@ -1,12 +1,10 @@
-///!MATCH_ERROR: jsii.Something#something changes the type of property when implementing jsii.ISomething (expected jsii.Superclass, found jsii.Subclass)
-
 export class Superclass {}
 export class Subclass extends Superclass {}
 
 export interface ISomething {
-    something: Superclass;
+  something: Superclass;
 }
 
 export class Something implements ISomething {
-    public something: Subclass = new Subclass();
+  public something: Subclass = new Subclass();
 }

packages/jsii/test/negatives/neg.implementation-changes-types.5.ts

@@ -1,18 +1,16 @@
-///!MATCH_ERROR: jsii.ISomethingElse#something changes the type of property when implementing jsii.ISomething (expected jsii.Superclass, found jsii.Subclass)
-
 export class Superclass {}
 export class Subclass extends Superclass {}
 
 export interface ISomething {
-    something: Superclass;
+  something: Superclass;
 }
 
 export interface ISomethingElse extends ISomething {
-    addUnrelatedMember: number;
+  addUnrelatedMember: number;
 }
 
 // Should still fail even though 2-level inheritance
 export class Something implements ISomethingElse {
-    public something: Subclass = new Subclass();
-    public addUnrelatedMember: number = 1;
+  public something: Subclass = new Subclass();
+  public addUnrelatedMember: number = 1;
 }

packages/jsii/test/negatives/neg.implementing-method-changes-optionality.1.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: jsii.Implementor#method changes the optionality of paramerter _optional when overriding jsii.AbstractClass (expected true, found false)
-
 // Attempt to change optionality of method parameter
 export abstract class AbstractClass {
   public abstract method(required: string, optional?: number): void;

packages/jsii/test/negatives/neg.implementing-method-changes-optionality.2.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: jsii.Implementor#method changes the optionality of paramerter _optional when overriding jsii.ParentClass (expected true, found false)
-
 // Attempt to change optionality of method parameter
 export class ParentClass {
   public method(_required: string, _optional?: number): void {

packages/jsii/test/negatives/neg.implementing-method-changes-optionality.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: jsii.Implementor#method changes the optionality of paramerter _optional when implementing jsii.IInterface (expected true, found false)
-
 // Attempt to change optionality of method parameter
 export interface IInterface {
   method(required: string, optional?: number): void;

packages/jsii/test/negatives/neg.implementing-property-changes-optionality.1.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: jsii.Implementor#property changes optionality of property when overriding jsii.AbstractClass
-
 // Attempt to change optionality of method parameter
 export abstract class AbstractClass {
   public abstract property?: string;

packages/jsii/test/negatives/neg.implementing-property-changes-optionality.2.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: jsii.Implementor#property changes optionality of property when overriding jsii.ParentClass
-
 // Attempt to change optionality of method parameter
 export class ParentClass {
   public property?: string = undefined;

packages/jsii/test/negatives/neg.implementing-property-changes-optionality.ts

@@ -1,5 +1,3 @@
-///!MATCH_ERROR: jsii.Implementor#property changes optionality of property when implementing jsii.IInterface
-
 // Attempt to change optionality of method parameter
 export interface IInterface {
   property?: string;