1 files changed, 63 insertions, 0 deletions
diff --git a/packages/server/src/git/diff.ts b/packages/server/src/git/diff.ts
new file mode 100644
index 0000000..a3ea375
--- /dev/null
+++ b/packages/server/src/git/diff.ts
@@ -0,0 +1,63 @@
+import { Diff as NodeGitDiff } from "nodegit";
+import { Patch } from "./patch";
+
+type PatchHeaderData = {
+	indexes: number[],
+	lengths: number[],
+	last: number | null
+}
+
+type DiffConstructorData = {
+	patch_buf: string,
+	patch_header_buf: string
+}
+
+export class Diff {
+	private _ng_diff: NodeGitDiff;
+
+	public raw_patches: string;
+	public patch_header_indexes: number[];
+	public patch_header_lengths: number[];
+
+	constructor(diff: NodeGitDiff, data: DiffConstructorData) {
+		this._ng_diff = diff;
+		this.raw_patches = data.patch_buf;
+
+		const raw_patches_arr = this.raw_patches.split("\n");
+		const patch_headers = data.patch_header_buf.split("\n");
+
+		const patch_header_data = patch_headers.reduce((result, line, index) => {
+			// The start of a patch header
+			if((/^diff --git/u).test(line)) {
+				result.indexes.push(raw_patches_arr.indexOf(line));
+
+				if(result.last !== null) {
+					result.lengths.push(patch_headers.slice(result.last, index).length);
+				}
+				result.last = index;
+			}
+
+			// Include the last patch header when the end is reached
+			if(index === patch_headers.length - 1 && result.last !== null) {
+				result.lengths.push(patch_headers.slice(result.last, index).length);
+			}
+
+			return result;
+		}, <PatchHeaderData>{ indexes: [], lengths: [], last: null });
+
+		this.patch_header_indexes = patch_header_data.indexes;
+		this.patch_header_lengths = patch_header_data.lengths;
+
+	}
+
+	async getPatches(): Promise<Patch[]> {
+		return (await this._ng_diff.patches()).map((patch, index) => new Patch(this, patch, index));
+	}
+
+	static async get(diff: NodeGitDiff): Promise<Diff> {
+		return new Diff(diff, {
+			patch_buf: String((await diff.toBuf(1))),
+			patch_header_buf: String((await diff.toBuf(2)))
+		});
+	}
+}
+\ No newline at end of file