feat: validation for handlers from manifest file (#1535)

* feat: validation for handlers from manifest file

* chore(dependencies): updated changesets for modified dependencies

* style run prettier

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: saihaj

.changeset/@graphprotocol_graph-cli-1535-dependencies.md

@@ -0,0 +1,7 @@
+---
+"@graphprotocol/graph-cli": patch
+---
+dependencies updates:
+  - Added dependency [`@babel/core@^7.20.5` ↗︎](https://www.npmjs.com/package/@babel/core/v/7.20.5) (to `dependencies`)
+  - Added dependency [`@babel/preset-typescript@^7.18.6` ↗︎](https://www.npmjs.com/package/@babel/preset-typescript/v/7.18.6) (to `dependencies`)
+  - Added dependency [`memoizee@^0.4.15` ↗︎](https://www.npmjs.com/package/memoizee/v/0.4.15) (to `dependencies`)

.changeset/six-crabs-crash.md

@@ -0,0 +1,5 @@
+---
+'@graphprotocol/graph-cli': minor
+---
+
+add validation for handlers from subgraph manifest

packages/cli/package.json

@@ -28,6 +28,8 @@
     "type-check": "tsc --noEmit"
   },
   "dependencies": {
+    "@babel/core": "^7.20.5",
+    "@babel/preset-typescript": "^7.18.6",
     "@float-capital/float-subgraph-uncrashable": "^0.0.0-alpha.4",
     "@oclif/core": "2.8.6",
     "@oclif/plugin-autocomplete": "^2.3.6",
@@ -48,6 +50,7 @@
     "ipfs-http-client": "55.0.0",
     "jayson": "4.0.0",
     "js-yaml": "3.14.1",
+    "memoizee": "^0.4.15",
     "prettier": "1.19.1",
     "request": "2.88.2",
     "semver": "7.4.0",
@@ -58,10 +61,12 @@
     "yaml": "1.10.2"
   },
   "devDependencies": {
+    "@types/babel__core": "^7.20.5",
     "@types/debug": "^4.1.7",
     "@types/fs-extra": "^9.0.13",
     "@types/jest": "^29.0.0",
     "@types/js-yaml": "^3.12.7",
+    "@types/memoizee": "^0.4.11",
     "@types/semver": "^7.3.13",
     "@types/which": "^2.0.1",
     "copyfiles": "^2.4.1",

packages/cli/src/compiler/index.ts

@@ -6,6 +6,8 @@ import * as toolbox from 'gluegun';
 import immutable from 'immutable';
 import type { IPFSHTTPClient } from 'ipfs-http-client';
 import yaml from 'js-yaml';
+import memo from 'memoizee';
+import { parseSync } from '@babel/core';
 import { Spinner, step, withSpinner } from '../command-helpers/spinner';
 import debug from '../debug';
 import { applyMigrations } from '../migrations';
@@ -16,6 +18,18 @@ import * as asc from './asc';
 
 const compilerDebug = debug('graph-cli:compiler');
 
+/** memoize the reading of the file so we don't have to read it every time */
+const readFile = memo((filename: string) => fs.readFileSync(filename, 'utf-8'));
+
+/** Memoized parser for Babel, so we can simply just read from cache  */
+const babelAst = memo((filename: string) => {
+  const data = readFile(filename);
+  return parseSync(data, {
+    presets: ['@babel/preset-typescript'],
+    filename,
+  });
+});
+
 interface CompilerOptions {
   ipfs: any;
   subgraphManifest: string;
@@ -350,12 +364,19 @@ export default class Compiler {
 
     try {
       const dataSourceName = dataSource.getIn(['name']);
-
       const baseDir = this.sourceDir;
       const absoluteMappingPath = path.resolve(baseDir, mappingPath);
       const inputFile = path.relative(baseDir, absoluteMappingPath);
+
       this._validateMappingContent(absoluteMappingPath);
 
+      const eventHandlers = dataSource.getIn(['mapping', 'eventHandlers']);
+      // TODO: improve the types
+      for (const eventHandler of (eventHandlers as any).toJS()) {
+        compilerDebug('Validating Event Handler %s', eventHandler.handler);
+        this._validateHandler(absoluteMappingPath, eventHandler.handler);
+      }
+
       // If the file has already been compiled elsewhere, just use that output
       // file and return early
       const inputCacheKey = this.cacheKeyForFile(absoluteMappingPath);
@@ -431,6 +452,13 @@ export default class Compiler {
       const inputFile = path.relative(baseDir, absoluteMappingPath);
       this._validateMappingContent(absoluteMappingPath);
 
+      const eventHandlers = templateName.getIn(['mapping', 'eventHandlers']);
+      // TODO: improve the types
+      for (const eventHandler of (eventHandlers as any).toJS()) {
+        compilerDebug('Validating Template handler %s', eventHandler.handler);
+        this._validateHandler(absoluteMappingPath, eventHandler.handler);
+      }
+
       // If the file has already been compiled elsewhere, just use that output
       // file and return early
       const inputCacheKey = this.cacheKeyForFile(absoluteMappingPath);
@@ -489,7 +517,7 @@ export default class Compiler {
   }
 
   _validateMappingContent(filePath: string) {
-    const data = fs.readFileSync(filePath);
+    const data = readFile(filePath);
     if (this.blockIpfsMethods && (data.includes('ipfs.cat') || data.includes('ipfs.map'))) {
       throw Error(`
       Subgraph Studio does not support mappings with ipfs methods.
@@ -499,6 +527,31 @@ export default class Compiler {
     }
   }
 
+  _validateHandler(filePath: string, handlerName: string) {
+    const baselAst = babelAst(filePath);
+
+    const body = baselAst?.program.body;
+
+    if (!body) {
+      throw Error(`Could not parse ${filePath}`);
+    }
+
+    const exportedFunctionNames = body
+      .map(statement => {
+        if (
+          statement.type === 'ExportNamedDeclaration' &&
+          statement?.declaration?.type === 'FunctionDeclaration'
+        ) {
+          return statement.declaration.id?.name;
+        }
+      })
+      .filter(Boolean);
+
+    if (!exportedFunctionNames.includes(handlerName)) {
+      throw Error(`Could not find handler '${handlerName}' in ${filePath}`);
+    }
+  }
+
   async writeSubgraphToOutputDirectory(protocol: Protocol, subgraph: immutable.Map<any, any>) {
     const displayDir = `${this.displayPath(this.options.outputDir)}${toolbox.filesystem.separator}`;