cleanup(snippet-bot): reduce memory footprint for large diffs (#1144)

* cleanup(snippet-bot): reduce memory footprint for large diffs fixes #1143 * refactor a bit more Co-authored-by: Benjamin E. Coe <[email protected]>
googleapis · Nov 17, 2020 · 03cf910 · 03cf910
1 parent 5495e7b
commit 03cf910
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Showing 3 changed files with 19 additions and 11 deletions.
diff --git a/packages/snippet-bot/src/region-tag-parser.ts b/packages/snippet-bot/src/region-tag-parser.ts
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 import parseDiff from 'parse-diff';
+import fetch from 'node-fetch';
 
 /**
  * The result for unmatched region tag checks.
@@ -57,15 +58,15 @@ const END_TAG_REGEX = /\[END ([^\]]*)\]/;
 /**
  * Detects region tag changes in a pull request and return the summary.
  */
-export function parseRegionTagsInPullRequest(
-  diff: string,
+export async function parseRegionTagsInPullRequest(
+  diffUrl: string,
   owner: string,
   repo: string,
   sha: string,
   headOwner: string,
   headRepo: string,
   headSha: string
-): ChangesInPullRequest {
+): Promise<ChangesInPullRequest> {
   const changes: Change[] = [];
   const files: string[] = [];
   const ret = {
@@ -74,7 +75,8 @@ export function parseRegionTagsInPullRequest(
     deleted: 0,
     files: files,
   };
-
+  const response = await fetch(diffUrl);
+  const diff = await response.text();
   const diffResult = parseDiff(diff);
   for (const file of diffResult) {
     if (file.to !== undefined && file.to !== '/dev/null') {

diff --git a/packages/snippet-bot/src/snippet-bot.ts b/packages/snippet-bot/src/snippet-bot.ts
@@ -326,11 +326,9 @@ ${bodyDetail}`
       // Check on pull requests.
 
       // Parse the PR diff and recognize added/deleted region tags.
-      const response = await fetch(context.payload.pull_request.diff_url);
-      const diff = await response.text();
 
-      const result = parseRegionTagsInPullRequest(
-        diff,
+      const result = await parseRegionTagsInPullRequest(
+        context.payload.pull_request.diff_url,
         context.payload.pull_request.base.repo.owner.login,
         context.payload.pull_request.base.repo.name,
         context.payload.pull_request.base.sha,

diff --git a/packages/snippet-bot/test/region-tag-parser.ts b/packages/snippet-bot/test/region-tag-parser.ts
@@ -22,15 +22,21 @@ import {resolve} from 'path';
 import * as fs from 'fs';
 import assert from 'assert';
 import {describe, it} from 'mocha';
+import nock from 'nock';
 
 const fixturesPath = resolve(__dirname, '../../test/fixtures');
 
+nock.disableNetConnect();
+
 describe('region-tag-parser', () => {
   const diff = fs.readFileSync(resolve(fixturesPath, 'diff.txt'), 'utf8');
   describe('parses a diff', () => {
-    it('returns a correct result', () => {
-      const result = parseRegionTagsInPullRequest(
-        diff,
+    it('returns a correct result', async () => {
+      const requests = nock('https://example.com')
+        .get('/diff.txt')
+        .reply(200, diff);
+      const result = await parseRegionTagsInPullRequest(
+        'https://example.com/diff.txt',
         'owner',
         'repo',
         'sha',
@@ -46,6 +52,8 @@ describe('region-tag-parser', () => {
       assert.strictEqual('headOwner', result.changes[1].owner);
       assert.strictEqual('headRepo', result.changes[1].repo);
       assert.strictEqual('headSha', result.changes[1].sha);
+
+      requests.done();
     });
   });
 });