refactor(core): move usage detection into usage strategy (#29815)

In order to support multiple strategies for detecting the query timing, the
query usage logic has been moved into a query usage strategy.

PR Close #29815

packages/core/schematics/migrations/static-queries/angular/super_class.ts

@@ -7,48 +7,13 @@
  */
 
 import * as ts from 'typescript';
-
-import {isFunctionLikeDeclaration} from '../../../utils/typescript/functions';
-import {hasModifier} from '../../../utils/typescript/nodes';
-import {getPropertyNameText} from '../../../utils/typescript/property_name';
-
-import {FunctionContext} from './declaration_usage_visitor';
 import {ClassMetadataMap} from './ng_query_visitor';
 
-
 /**
- * Updates the specified function context to map abstract super-class class members
- * to their implementation TypeScript nodes. This allows us to run the declaration visitor
- * for the super class with the context of the "baseClass" (e.g. with implemented abstract
- * class members)
+ * Gets all chained super-class TypeScript declarations for the given class
+ * by using the specified class metadata map.
  */
-export function updateSuperClassAbstractMembersContext(
-    baseClass: ts.ClassDeclaration, context: FunctionContext, classMetadataMap: ClassMetadataMap) {
-  getSuperClassDeclarations(baseClass, classMetadataMap).forEach(superClassDecl => {
-    superClassDecl.members.forEach(superClassMember => {
-      if (!superClassMember.name || !hasModifier(superClassMember, ts.SyntaxKind.AbstractKeyword)) {
-        return;
-      }
-
-      // Find the matching implementation of the abstract declaration from the super class.
-      const baseClassImpl = baseClass.members.find(
-          baseClassMethod => !!baseClassMethod.name &&
-              getPropertyNameText(baseClassMethod.name) ===
-                  getPropertyNameText(superClassMember.name !));
-
-      if (!baseClassImpl || !isFunctionLikeDeclaration(baseClassImpl) || !baseClassImpl.body) {
-        return;
-      }
-
-      if (!context.has(superClassMember)) {
-        context.set(superClassMember, baseClassImpl);
-      }
-    });
-  });
-}
-
-/** Gets all super-class TypeScript declarations for the given class. */
-function getSuperClassDeclarations(
+export function getSuperClassDeclarations(
     classDecl: ts.ClassDeclaration, classMetadataMap: ClassMetadataMap) {
   const declarations: ts.ClassDeclaration[] = [];
 

packages/core/schematics/migrations/static-queries/google3/explicitQueryTimingRule.ts

@@ -11,9 +11,9 @@ import * as ts from 'typescript';
 
 import {NgComponentTemplateVisitor} from '../../../utils/ng_component_template';
 import {visitAllNodes} from '../../../utils/typescript/visit_nodes';
-import {analyzeNgQueryUsage} from '../angular/analyze_query_usage';
 import {NgQueryResolveVisitor} from '../angular/ng_query_visitor';
 import {QueryTiming} from '../angular/query-definition';
+import {QueryUsageStrategy} from '../strategies/usage_strategy/usage_strategy';
 import {getTransformedQueryCallExpr} from '../transform';
 
 const FAILURE_MESSAGE = 'Query does not explicitly specify its timing. Read more here: ' +
@@ -52,6 +52,7 @@ export class Rule extends Rules.TypedRule {
     });
 
     const queries = resolvedQueries.get(sourceFile);
+    const usageStrategy = new QueryUsageStrategy(classMetadata, typeChecker);
 
     // No queries detected for the given source file.
     if (!queries) {
@@ -62,7 +63,7 @@ export class Rule extends Rules.TypedRule {
     // query definitions to explicitly declare the query timing (static or dynamic)
     queries.forEach(q => {
       const queryExpr = q.decorator.node.expression;
-      const timing = analyzeNgQueryUsage(q, classMetadata, typeChecker);
+      const timing = usageStrategy.detectTiming(q);
       const transformedNode = getTransformedQueryCallExpr(q, timing);
 
       if (!transformedNode) {

packages/core/schematics/migrations/static-queries/index.ts

@@ -15,8 +15,8 @@ import {getProjectTsConfigPaths} from '../../utils/project_tsconfig_paths';
 import {parseTsconfigFile} from '../../utils/typescript/parse_tsconfig';
 import {visitAllNodes} from '../../utils/typescript/visit_nodes';
 
-import {analyzeNgQueryUsage} from './angular/analyze_query_usage';
 import {NgQueryResolveVisitor} from './angular/ng_query_visitor';
+import {QueryUsageStrategy} from './strategies/usage_strategy/usage_strategy';
 import {getTransformedQueryCallExpr} from './transform';
 
 
@@ -83,6 +83,8 @@ function runStaticQueryMigration(tree: Tree, tsconfigPath: string, basePath: str
     }
   });
 
+  const usageStrategy = new QueryUsageStrategy(classMetadata, typeChecker);
+
   // Walk through all source files that contain resolved queries and update
   // the source files if needed. Note that we need to update multiple queries
   // within a source file within the same recorder in order to not throw off
@@ -94,7 +96,7 @@ function runStaticQueryMigration(tree: Tree, tsconfigPath: string, basePath: str
     // query definitions to explicitly declare the query timing (static or dynamic)
     queries.forEach(q => {
       const queryExpr = q.decorator.node.expression;
-      const timing = analyzeNgQueryUsage(q, classMetadata, typeChecker);
+      const timing = usageStrategy.detectTiming(q);
       const transformedNode = getTransformedQueryCallExpr(q, timing);
 
       if (!transformedNode) {

packages/core/schematics/migrations/static-queries/strategies/usage_strategy/declaration_usage_visitor.ts

@@ -7,7 +7,7 @@
  */
 
 import * as ts from 'typescript';
-import {isFunctionLikeDeclaration, unwrapExpression} from '../../../utils/typescript/functions';
+import {isFunctionLikeDeclaration, unwrapExpression} from '../../../../utils/typescript/functions';
 
 export type FunctionContext = Map<ts.Node, ts.Node>;
 

packages/core/schematics/migrations/static-queries/strategies/usage_strategy/super_class_context.ts

@@ -0,0 +1,49 @@
+/**
+ * @license
+ * Copyright Google Inc. 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 * as ts from 'typescript';
+
+import {isFunctionLikeDeclaration} from '../../../../utils/typescript/functions';
+import {hasModifier} from '../../../../utils/typescript/nodes';
+import {getPropertyNameText} from '../../../../utils/typescript/property_name';
+import {ClassMetadataMap} from '../../angular/ng_query_visitor';
+import {getSuperClassDeclarations} from '../../angular/super_class';
+
+import {FunctionContext} from './declaration_usage_visitor';
+
+
+/**
+ * Updates the specified function context to map abstract super-class class members
+ * to their implementation TypeScript nodes. This allows us to run the declaration visitor
+ * for the super class with the context of the "baseClass" (e.g. with implemented abstract
+ * class members)
+ */
+export function updateSuperClassAbstractMembersContext(
+    baseClass: ts.ClassDeclaration, context: FunctionContext, classMetadataMap: ClassMetadataMap) {
+  getSuperClassDeclarations(baseClass, classMetadataMap).forEach(superClassDecl => {
+    superClassDecl.members.forEach(superClassMember => {
+      if (!superClassMember.name || !hasModifier(superClassMember, ts.SyntaxKind.AbstractKeyword)) {
+        return;
+      }
+
+      // Find the matching implementation of the abstract declaration from the super class.
+      const baseClassImpl = baseClass.members.find(
+          baseClassMethod => !!baseClassMethod.name &&
+              getPropertyNameText(baseClassMethod.name) ===
+                  getPropertyNameText(superClassMember.name !));
+
+      if (!baseClassImpl || !isFunctionLikeDeclaration(baseClassImpl) || !baseClassImpl.body) {
+        return;
+      }
+
+      if (!context.has(superClassMember)) {
+        context.set(superClassMember, baseClassImpl);
+      }
+    });
+  });
+}

packages/core/schematics/migrations/static-queries/strategies/usage_strategy/template_usage_visitor.ts

@@ -13,7 +13,7 @@ import {BoundAttribute, BoundEvent, BoundText, Element, Node, NullVisitor, Templ
  * AST visitor that traverses the Render3 HTML AST in order to check if the given
  * query property is accessed statically in the template.
  */
-export class QueryReadHtmlVisitor extends NullVisitor {
+export class TemplateUsageVisitor extends NullVisitor {
   private hasQueryTemplateReference = false;
   private expressionAstVisitor = new ExpressionAstVisitor(this.queryPropertyName);
 

packages/core/schematics/migrations/static-queries/strategies/usage_strategy/usage_strategy.ts

@@ -8,14 +8,15 @@
 
 import * as ts from 'typescript';
 
-import {parseHtmlGracefully} from '../../../utils/parse_html';
-import {hasPropertyNameText} from '../../../utils/typescript/property_name';
+import {parseHtmlGracefully} from '../../../../utils/parse_html';
+import {hasPropertyNameText} from '../../../../utils/typescript/property_name';
+import {ClassMetadataMap} from '../../angular/ng_query_visitor';
+import {NgQueryDefinition, QueryTiming, QueryType} from '../../angular/query-definition';
+import {TimingStrategy} from '../../timing-strategy';
 
 import {DeclarationUsageVisitor, FunctionContext} from './declaration_usage_visitor';
-import {ClassMetadataMap} from './ng_query_visitor';
-import {NgQueryDefinition, QueryTiming, QueryType} from './query-definition';
-import {QueryReadHtmlVisitor} from './query_read_html_visitor';
-import {updateSuperClassAbstractMembersContext} from './super_class';
+import {updateSuperClassAbstractMembersContext} from './super_class_context';
+import {TemplateUsageVisitor} from './template_usage_visitor';
 
 
 /**
@@ -29,17 +30,25 @@ const STATIC_QUERY_LIFECYCLE_HOOKS = {
 };
 
 /**
- * Analyzes the usage of the given query and determines the query timing based
- * on the current usage of the query.
+ * Query timing strategy that determines the timing of a given query by inspecting how
+ * the query is accessed within the project's TypeScript source files. Read more about
+ * this strategy here: https://hackmd.io/s/Hymvc2OKE
  */
-export function analyzeNgQueryUsage(
-    query: NgQueryDefinition, classMetadata: ClassMetadataMap,
-    typeChecker: ts.TypeChecker): QueryTiming {
-  return isQueryUsedStatically(query.container, query, classMetadata, typeChecker, []) ?
-      QueryTiming.STATIC :
-      QueryTiming.DYNAMIC;
+export class QueryUsageStrategy implements TimingStrategy {
+  constructor(private classMetadata: ClassMetadataMap, private typeChecker: ts.TypeChecker) {}
+
+  /**
+   * Analyzes the usage of the given query and determines the query timing based
+   * on the current usage of the query.
+   */
+  detectTiming(query: NgQueryDefinition): QueryTiming {
+    return isQueryUsedStatically(query.container, query, this.classMetadata, this.typeChecker, []) ?
+        QueryTiming.STATIC :
+        QueryTiming.DYNAMIC;
+  }
 }
 
+
 /**
  * Checks whether a given query is used statically within the given class, its super
  * class or derived classes.
@@ -79,7 +88,7 @@ function isQueryUsedStatically(
   if (classMetadata.template && hasPropertyNameText(query.property.name)) {
     const template = classMetadata.template;
     const parsedHtml = parseHtmlGracefully(template.content, template.filePath);
-    const htmlVisitor = new QueryReadHtmlVisitor(query.property.name.text);
+    const htmlVisitor = new TemplateUsageVisitor(query.property.name.text);
 
     if (parsedHtml && htmlVisitor.isQueryUsedStatically(parsedHtml)) {
       return true;

packages/core/schematics/migrations/static-queries/timing-strategy.ts

@@ -0,0 +1,11 @@
+/**
+ * @license
+ * Copyright Google Inc. 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 {NgQueryDefinition, QueryTiming} from './angular/query-definition';
+
+export interface TimingStrategy { detectTiming(query: NgQueryDefinition): QueryTiming; }