diagnostics.ts

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import ts from 'typescript';

import {ErrorCode, FatalDiagnosticError, makeDiagnostic, makeRelatedInformation} from '../../../diagnostics';
import {Reference} from '../../../imports';
import {HostDirectiveMeta, MetadataReader} from '../../../metadata';
import {describeResolvedType, DynamicValue, PartialEvaluator, ResolvedValue, traceDynamicValue} from '../../../partial_evaluator';
import {ClassDeclaration, ReflectionHost} from '../../../reflection';
import {DeclarationData, LocalModuleScopeRegistry} from '../../../scope';
import {identifierOfNode} from '../../../util/src/typescript';

import {InjectableClassRegistry} from './injectable_registry';
import {isAbstractClassDeclaration, readBaseClass} from './util';


/**
 * Create a `ts.Diagnostic` which indicates the given class is part of the declarations of two or
 * more NgModules.
 *
 * The resulting `ts.Diagnostic` will have a context entry for each NgModule showing the point where
 * the directive/pipe exists in its `declarations` (if possible).
 */
export function makeDuplicateDeclarationError(
    node: ClassDeclaration, data: DeclarationData[], kind: string): ts.Diagnostic {
  const context: ts.DiagnosticRelatedInformation[] = [];
  for (const decl of data) {
    if (decl.rawDeclarations === null) {
      continue;
    }
    // Try to find the reference to the declaration within the declarations array, to hang the
    // error there. If it can't be found, fall back on using the NgModule's name.
    const contextNode = decl.ref.getOriginForDiagnostics(decl.rawDeclarations, decl.ngModule.name);
    context.push(makeRelatedInformation(
        contextNode,
        `'${node.name.text}' is listed in the declarations of the NgModule '${
            decl.ngModule.name.text}'.`));
  }

  // Finally, produce the diagnostic.
  return makeDiagnostic(
      ErrorCode.NGMODULE_DECLARATION_NOT_UNIQUE, node.name,
      `The ${kind} '${node.name.text}' is declared by more than one NgModule.`, context);
}


/**
 * Creates a `FatalDiagnosticError` for a node that did not evaluate to the expected type. The
 * diagnostic that is created will include details on why the value is incorrect, i.e. it includes
 * a representation of the actual type that was unsupported, or in the case of a dynamic value the
 * trace to the node where the dynamic value originated.
 *
 * @param node The node for which the diagnostic should be produced.
 * @param value The evaluated value that has the wrong type.
 * @param messageText The message text of the error.
 */
export function createValueHasWrongTypeError(
    node: ts.Node, value: ResolvedValue, messageText: string): FatalDiagnosticError {
  let chainedMessage: string;
  let relatedInformation: ts.DiagnosticRelatedInformation[]|undefined;
  if (value instanceof DynamicValue) {
    chainedMessage = 'Value could not be determined statically.';
    relatedInformation = traceDynamicValue(node, value);
  } else if (value instanceof Reference) {
    const target = value.debugName !== null ? `'${value.debugName}'` : 'an anonymous declaration';
    chainedMessage = `Value is a reference to ${target}.`;

    const referenceNode = identifierOfNode(value.node) ?? value.node;
    relatedInformation = [makeRelatedInformation(referenceNode, 'Reference is declared here.')];
  } else {
    chainedMessage = `Value is of type '${describeResolvedType(value)}'.`;
  }

  const chain: ts.DiagnosticMessageChain = {
    messageText,
    category: ts.DiagnosticCategory.Error,
    code: 0,
    next: [{
      messageText: chainedMessage,
      category: ts.DiagnosticCategory.Message,
      code: 0,
    }]
  };

  return new FatalDiagnosticError(ErrorCode.VALUE_HAS_WRONG_TYPE, node, chain, relatedInformation);
}

/**
 * Gets the diagnostics for a set of provider classes.
 * @param providerClasses Classes that should be checked.
 * @param providersDeclaration Node that declares the providers array.
 * @param registry Registry that keeps track of the registered injectable classes.
 */
export function getProviderDiagnostics(
    providerClasses: Set<Reference<ClassDeclaration>>, providersDeclaration: ts.Expression,
    registry: InjectableClassRegistry): ts.Diagnostic[] {
  const diagnostics: ts.Diagnostic[] = [];

  for (const provider of providerClasses) {
    const injectableMeta = registry.getInjectableMeta(provider.node);
    if (injectableMeta !== null) {
      // The provided type is recognized as injectable, so we don't report a diagnostic for this
      // provider.
      continue;
    }

    const contextNode = provider.getOriginForDiagnostics(providersDeclaration);
    diagnostics.push(makeDiagnostic(
        ErrorCode.UNDECORATED_PROVIDER, contextNode,
        `The class '${
            provider.node.name
                .text}' cannot be created via dependency injection, as it does not have an Angular decorator. This will result in an error at runtime.

Either add the @Injectable() decorator to '${
            provider.node.name
                .text}', or configure a different provider (such as a provider with 'useFactory').
`,
        [makeRelatedInformation(provider.node, `'${provider.node.name.text}' is declared here.`)]));
  }

  return diagnostics;
}

export function getDirectiveDiagnostics(
    node: ClassDeclaration, injectableRegistry: InjectableClassRegistry,
    evaluator: PartialEvaluator, reflector: ReflectionHost, scopeRegistry: LocalModuleScopeRegistry,
    strictInjectionParameters: boolean, kind: 'Directive'|'Component'): ts.Diagnostic[]|null {
  let diagnostics: ts.Diagnostic[]|null = [];

  const addDiagnostics = (more: ts.Diagnostic|ts.Diagnostic[]|null) => {
    if (more === null) {
      return;
    } else if (diagnostics === null) {
      diagnostics = Array.isArray(more) ? more : [more];
    } else if (Array.isArray(more)) {
      diagnostics.push(...more);
    } else {
      diagnostics.push(more);
    }
  };

  const duplicateDeclarations = scopeRegistry.getDuplicateDeclarations(node);

  if (duplicateDeclarations !== null) {
    addDiagnostics(makeDuplicateDeclarationError(node, duplicateDeclarations, kind));
  }

  addDiagnostics(checkInheritanceOfInjectable(
      node, injectableRegistry, reflector, evaluator, strictInjectionParameters, kind));
  return diagnostics;
}

export function validateHostDirectives(
    origin: ts.Expression, hostDirectives: HostDirectiveMeta[], metaReader: MetadataReader) {
  const diagnostics: ts.DiagnosticWithLocation[] = [];

  for (const current of hostDirectives) {
    const hostMeta = metaReader.getDirectiveMetadata(current.directive);

    if (hostMeta === null) {
      diagnostics.push(makeDiagnostic(
          ErrorCode.HOST_DIRECTIVE_INVALID, current.directive.getOriginForDiagnostics(origin),
          `${
              current.directive
                  .debugName} must be a standalone directive to be used as a host directive`));
      continue;
    }

    if (!hostMeta.isStandalone) {
      diagnostics.push(makeDiagnostic(
          ErrorCode.HOST_DIRECTIVE_NOT_STANDALONE,
          current.directive.getOriginForDiagnostics(origin),
          `Host directive ${hostMeta.name} must be standalone`));
    }

    if (hostMeta.isComponent) {
      diagnostics.push(makeDiagnostic(
          ErrorCode.HOST_DIRECTIVE_COMPONENT, current.directive.getOriginForDiagnostics(origin),
          `Host directive ${hostMeta.name} cannot be a component`));
    }
  }

  return diagnostics;
}

export function getUndecoratedClassWithAngularFeaturesDiagnostic(node: ClassDeclaration):
    ts.Diagnostic {
  return makeDiagnostic(
      ErrorCode.UNDECORATED_CLASS_USING_ANGULAR_FEATURES, node.name,
      `Class is using Angular features but is not decorated. Please add an explicit ` +
          `Angular decorator.`);
}

export function checkInheritanceOfInjectable(
    node: ClassDeclaration, injectableRegistry: InjectableClassRegistry, reflector: ReflectionHost,
    evaluator: PartialEvaluator, strictInjectionParameters: boolean,
    kind: 'Directive'|'Component'|'Pipe'|'Injectable'): ts.Diagnostic|null {
  const classWithCtor = findInheritedCtor(node, injectableRegistry, reflector, evaluator);
  if (classWithCtor === null || classWithCtor.isCtorValid) {
    // The class does not inherit a constructor, or the inherited constructor is compatible
    // with DI; no need to report a diagnostic.
    return null;
  }

  if (!classWithCtor.isDecorated) {
    // The inherited constructor exists in a class that does not have an Angular decorator.
    // This is an error, as there won't be a factory definition available for DI to invoke
    // the constructor.
    return getInheritedUndecoratedCtorDiagnostic(node, classWithCtor.ref, kind);
  }

  if (!strictInjectionParameters || isAbstractClassDeclaration(node)) {
    // An invalid constructor is only reported as error under `strictInjectionParameters` and
    // only for concrete classes; follow the same exclusions for derived types.
    return null;
  }

  return getInheritedInvalidCtorDiagnostic(node, classWithCtor.ref, kind);
}

interface ClassWithCtor {
  ref: Reference<ClassDeclaration>;
  isCtorValid: boolean;
  isDecorated: boolean;
}

export function findInheritedCtor(
    node: ClassDeclaration, injectableRegistry: InjectableClassRegistry, reflector: ReflectionHost,
    evaluator: PartialEvaluator): ClassWithCtor|null {
  if (!reflector.isClass(node) || reflector.getConstructorParameters(node) !== null) {
    // We should skip nodes that aren't classes. If a constructor exists, then no base class
    // definition is required on the runtime side - it's legal to inherit from any class.
    return null;
  }

  // The extends clause is an expression which can be as dynamic as the user wants. Try to
  // evaluate it, but fall back on ignoring the clause if it can't be understood. This is a View
  // Engine compatibility hack: View Engine ignores 'extends' expressions that it cannot understand.
  let baseClass = readBaseClass(node, reflector, evaluator);

  while (baseClass !== null) {
    if (baseClass === 'dynamic') {
      return null;
    }

    const injectableMeta = injectableRegistry.getInjectableMeta(baseClass.node);
    if (injectableMeta !== null) {
      if (injectableMeta.ctorDeps !== null) {
        // The class has an Angular decorator with a constructor.
        return {
          ref: baseClass,
          isCtorValid: injectableMeta.ctorDeps !== 'invalid',
          isDecorated: true,
        };
      }
    } else {
      const baseClassConstructorParams = reflector.getConstructorParameters(baseClass.node);
      if (baseClassConstructorParams !== null) {
        // The class is not decorated, but it does have constructor. An undecorated class is only
        // allowed to have a constructor without parameters, otherwise it is invalid.
        return {
          ref: baseClass,
          isCtorValid: baseClassConstructorParams.length === 0,
          isDecorated: false,
        };
      }
    }

    // Go up the chain and continue
    baseClass = readBaseClass(baseClass.node, reflector, evaluator);
  }

  return null;
}

function getInheritedInvalidCtorDiagnostic(
    node: ClassDeclaration, baseClass: Reference,
    kind: 'Directive'|'Component'|'Pipe'|'Injectable') {
  const baseClassName = baseClass.debugName;

  return makeDiagnostic(
      ErrorCode.INJECTABLE_INHERITS_INVALID_CONSTRUCTOR, node.name,
      `The ${kind.toLowerCase()} ${node.name.text} inherits its constructor from ${
          baseClassName}, ` +
          `but the latter has a constructor parameter that is not compatible with dependency injection. ` +
          `Either add an explicit constructor to ${node.name.text} or change ${
              baseClassName}'s constructor to ` +
          `use parameters that are valid for DI.`);
}

function getInheritedUndecoratedCtorDiagnostic(
    node: ClassDeclaration, baseClass: Reference,
    kind: 'Directive'|'Component'|'Pipe'|'Injectable') {
  const baseClassName = baseClass.debugName;
  const baseNeedsDecorator =
      kind === 'Component' || kind === 'Directive' ? 'Directive' : 'Injectable';

  return makeDiagnostic(
      ErrorCode.DIRECTIVE_INHERITS_UNDECORATED_CTOR, node.name,
      `The ${kind.toLowerCase()} ${node.name.text} inherits its constructor from ${
          baseClassName}, ` +
          `but the latter does not have an Angular decorator of its own. Dependency injection will not be able to ` +
          `resolve the parameters of ${baseClassName}'s constructor. Either add a @${
              baseNeedsDecorator} decorator ` +
          `to ${baseClassName}, or add an explicit constructor to ${node.name.text}.`);
}