feat(patch text to hunk bounds): support regex for patch texts

src/github-handler/comment-handler/diff-text-handler.ts

@@ -0,0 +1,91 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import {Range} from '../../types';
+
+const REGEX_INDEX_UPDATED_HUNK = 2;
+
+/**
+ * Example output of one output of one regex exec
+ *
+ * '@@ -0,0 +1,12 @@\n', // original text
+ * '0,0', // original hunk
+ * '1,12', // new hunk
+ * index: 0,
+ * input: '@@ -0,0 +1,12 @@\n+Hello world%0A',
+ * groups: undefined
+ *
+ */
+const REGEX_MANY_MANY = /@@ -([0-9]+,[0-9]+) \+([0-9]+,[0-9]+) @@\n/g;
+const REGEX_ONE_MANY = /@@ -([0-9]+) \+([0-9]+,[0-9]+) @@\n/g;
+const REGEX_ONE_ONE = /@@ -([0-9]+) \+([0-9]+) @@\n/g;
+const REGEX_MANY_ONE = /@@ -([0-9]+) \+([0-9]+,[0-9]+) @@\n/g;
+
+/**
+ * Parses the GitHub line-based patch text
+ * @param {string} patchText
+ * @returns patch ranges
+ */
+export function getGitHubPatchRanges(patchText: string): Range[] {
+  const ranges: Range[] = [];
+  for (
+    let patch = REGEX_MANY_MANY.exec(patchText);
+    patch !== null;
+    patch = REGEX_MANY_MANY.exec(patchText)
+  ) {
+    // stricly interested in the updated/current github file content
+    const patchData = patch[REGEX_INDEX_UPDATED_HUNK].split(',');
+    // the line number ranges of the updated text
+    const start = parseInt(patchData[0]);
+    const offset = parseInt(patchData[1]);
+    const range: Range = {start, end: start + offset};
+    ranges.push(range);
+  }
+  for (
+    let patch = REGEX_ONE_MANY.exec(patchText);
+    patch !== null;
+    patch = REGEX_ONE_MANY.exec(patchText)
+  ) {
+    // stricly interested in the updated/current github file content
+    const patchData = patch[REGEX_INDEX_UPDATED_HUNK].split(',');
+    // the line number ranges of the updated text
+    const start = parseInt(patchData[0]);
+    const offset = parseInt(patchData[1]);
+    const range: Range = {start, end: start + offset};
+    ranges.push(range);
+  }
+  for (
+    let patch = REGEX_ONE_ONE.exec(patchText);
+    patch !== null;
+    patch = REGEX_ONE_ONE.exec(patchText)
+  ) {
+    // stricly interested in the updated/current github file content
+    // the line number ranges of the updated text
+    const start = parseInt(patch[REGEX_INDEX_UPDATED_HUNK]);
+    const range: Range = {start, end: start + 1};
+    ranges.push(range);
+  }
+  for (
+    let patch = REGEX_MANY_ONE.exec(patchText);
+    patch !== null;
+    patch = REGEX_MANY_ONE.exec(patchText)
+  ) {
+    // stricly interested in the updated/current github file content
+    // the line number ranges of the updated text
+    const start = parseInt(patch[REGEX_INDEX_UPDATED_HUNK]);
+    const range: Range = {start, end: start + 1};
+    ranges.push(range);
+  }
+  return ranges;
+}

src/types/index.ts

@@ -116,3 +116,31 @@ export interface CreatePullRequest {
   // Whether or not maintainers can modify the PR.
   maintainersCanModify: boolean;
 }
+
+/**
+ * The file content of the original content and the patched content
+ */
+export interface RawContent {
+  readonly old_content: string;
+  readonly new_content: string;
+}
+
+/**
+ * A range object defined by lower boundary as 'start' and upper boundary as 'end'
+ */
+export interface Range {
+  readonly start: number;
+  readonly end: number;
+}
+
+/**
+ * The range of a patch along with the raw file content
+ */
+export interface Patch extends Range {
+  readonly raw_content: string;
+}
+
+export type FilePatches = Map<string, Patch[]>;
+export type RawChanges = Map<string, RawContent>;
+export type PatchText = Map<string, string>;
+export type FileRanges = Map<string, Range[]>;

test/regex-patch.ts

@@ -0,0 +1,88 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import {expect} from 'chai';
+import {describe, it} from 'mocha';
+import {getGitHubPatchRanges} from '../src/github-handler/comment-handler/diff-text-handler';
+
+describe('Getting patch range from patch text', async () => {
+  describe('GitHub patch text', () => {
+    const gitHubListFilesData = [
+      {
+        sha: 'a1d470fa4d7b04450715e3e02d240a34517cd988',
+        filename: 'Readme.md',
+        status: 'modified',
+        additions: 4,
+        deletions: 1,
+        changes: 5,
+        blob_url:
+          'https://github.com/TomKristie/HelloWorld/blob/eb53f3871f56e8dd6321e44621fe6ac2da1bc120/Readme.md',
+        raw_url:
+          'https://github.com/TomKristie/HelloWorld/raw/eb53f3871f56e8dd6321e44621fe6ac2da1bc120/Readme.md',
+        contents_url:
+          'https://api.github.com/repos/TomKristie/HelloWorld/contents/Readme.md?ref=eb53f3871f56e8dd6321e44621fe6ac2da1bc120',
+        patch:
+          '@@ -1,2 +1,5 @@\n Hello world\n-!\n+Goodbye World\n+gOodBYE world\n+\n+Goodbye World',
+      },
+      {
+        sha: '8b137891791fe96927ad78e64b0aad7bded08bdc',
+        filename: 'foo/foo.txt',
+        status: 'modified',
+        additions: 1,
+        deletions: 1,
+        changes: 2,
+        blob_url:
+          'https://github.com/TomKristie/HelloWorld/blob/eb53f3871f56e8dd6321e44621fe6ac2da1bc120/foo/foo.txt',
+        raw_url:
+          'https://github.com/TomKristie/HelloWorld/raw/eb53f3871f56e8dd6321e44621fe6ac2da1bc120/foo/foo.txt',
+        contents_url:
+          'https://api.github.com/repos/TomKristie/HelloWorld/contents/foo/foo.txt?ref=eb53f3871f56e8dd6321e44621fe6ac2da1bc120',
+        patch: '@@ -1 +1 @@\n-Hello foo\n+',
+      },
+      {
+        sha: '3b18e512dba79e4c8300dd08aeb37f8e728b8dad',
+        filename: 'helloworld.txt',
+        status: 'removed',
+        additions: 0,
+        deletions: 1,
+        changes: 1,
+        blob_url:
+          'https://github.com/TomKristie/HelloWorld/blob/f5da827a725a701302da7db2da16b1678f52fdcc/helloworld.txt',
+        raw_url:
+          'https://github.com/TomKristie/HelloWorld/raw/f5da827a725a701302da7db2da16b1678f52fdcc/helloworld.txt',
+        contents_url:
+          'https://api.github.com/repos/TomKristie/HelloWorld/contents/helloworld.txt?ref=f5da827a725a701302da7db2da16b1678f52fdcc',
+        patch: '@@ -1 +0,0 @@\n-hello world',
+      },
+    ];
+    it('parses original text for multiline modifies', () => {
+      const patch = gitHubListFilesData[0];
+      const ranges = getGitHubPatchRanges(patch.patch);
+      expect(ranges[0].start).equals(1);
+      expect(ranges[0].end).equals(6);
+    });
+    it('parses original text for single line modifies at the start of the file', () => {
+      const patch = gitHubListFilesData[1];
+      const ranges = getGitHubPatchRanges(patch.patch);
+      expect(ranges[0].start).equals(1);
+      expect(ranges[0].end).equals(2);
+    });
+    it('parses original text for single line deletes', () => {
+      const patch = gitHubListFilesData[2];
+      const ranges = getGitHubPatchRanges(patch.patch);
+      expect(ranges[0].start).equals(0);
+      expect(ranges[0].end).equals(0);
+    });
+  });
+});