create method to return ParsedDiff objects from code lines

Summary:
Context: Code Patch suggestion returns the code diff in the format of two strings (oldCode and newCode). Need a way to parse it into ParsedDiff object to fit the structures that ISL already have.

Will be used in later diff

Reviewed By: evangrayk

Differential Revision: D64094142

fbshipit-source-id: 2807532054704ea7b4d98ed57e895ea77fbb2a3c

addons/shared/__tests__/parse.test.ts

@@ -5,7 +5,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {parsePatch} from '../patch/parse';
+import {splitLines} from '../diff';
+import {parseParsedDiff, parsePatch} from '../patch/parse';
 
 describe('patch/parse', () => {
  it('should parse basic modified patch', () => {
@@ -256,3 +257,48 @@ new mode 100755
  expect(() => parsePatch(patch)).toThrow("invalid format 'old mode XXX'");
  });
 });
+
+describe('createParsedDiffWithLines', () => {
+ it('return no hunks for empty lines', () => {
+ expect(parseParsedDiff([], [], 1)).toMatchObject({hunks: []});
+ });
+
+ it('returns no hunks when comparing same lines', () => {
+ const lines = splitLines('a\nb\nc\nd\ne\n');
+ expect(parseParsedDiff(lines, lines, 1)).toMatchObject({hunks: []});
+ });
+
+ it('return all "-" for old code and "=" for new code for totally different contents', () => {
+ const aLines = splitLines('x\ny\n');
+ const bLines = splitLines('a\nb\nc\n');
+ expect(parseParsedDiff(aLines, bLines, 1)).toMatchObject({
+ hunks: [
+ {
+ oldStart: 1,
+ oldLines: 2,
+ newStart: 1,
+ newLines: 3,
+ lines: ['-x\n', '-y\n', '+a\n', '+b\n', '+c\n'],
+ linedelimiters: ['\n', '\n', '\n', '\n', '\n'],
+ },
+ ],
+ });
+ });
+
+ it('reutrn for when a line was changed in the middle', () => {
+ const aLines = splitLines('a\nb\nc\nd\ne\n');
+ const bLines = splitLines('a\nb\nc\nd1\nd2\ne\n');
+ expect(parseParsedDiff(aLines, bLines, 1)).toMatchObject({
+ hunks: [
+ {
+ oldStart: 4,
+ oldLines: 1,
+ newStart: 4,
+ newLines: 2,
+ lines: ['-d\n', '+d1\n', '+d2\n'],
+ linedelimiters: ['\n', '\n', '\n'],
+ },
+ ],
+ });
+ });
+});

addons/shared/patch/parse.ts

@@ -5,6 +5,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import {diffBlocks} from '../diff';
+
 export type Hunk = {
  oldStart: number;
  oldLines: number;
@@ -264,3 +266,44 @@ export function parsePatch(patch: string): ParsedDiff[] {
 
  return list;
 }
+
+export function parseParsedDiff(
+ oldCodeLines: string[],
+ newCodeLines: string[],
+ lineNumber: number,
+ oldFileName?: string,
+ newFileName?: string,
+): ParsedDiff {
+ const hunks: Hunk[] = [];
+ const blocks = diffBlocks(oldCodeLines, newCodeLines);
+
+ blocks.forEach(block => {
+ if (block[0] === '=') {
+ return;
+ }
+
+ const oldRange = [block[1][0], block[1][1]];
+ const newRange = [block[1][2], block[1][3]];
+
+ const oldLines = oldCodeLines.slice(oldRange[0], oldRange[1]).map(codeStr => '-' + codeStr);
+ const newLines = newCodeLines.slice(newRange[0], newRange[1]).map(codeStr => '+' + codeStr);
+ const delimiters = new Array(oldLines.length + newLines.length).fill('\n');
+
+ const hunk: Hunk = {
+ oldStart: lineNumber + oldRange[0],
+ oldLines: oldLines.length ?? 0,
+ newStart: lineNumber + newRange[0],
+ newLines: newLines.length ?? 0,
+ lines: oldLines.concat(newLines),
+ linedelimiters: delimiters,
+ };
+
+ hunks.push(hunk);
+ });
+
+ return {
+ oldFileName,
+ newFileName,
+ hunks,
+ } as ParsedDiff;
+}