Back out @lib indirection in tsconfig.json (#111)

codex-cli/src/parse-apply-patch.ts

@@ -0,0 +1,112 @@
+export type ApplyPatchCreateFileOp = {
+  type: "create";
+  path: string;
+  content: string;
+};
+
+export type ApplyPatchDeleteFileOp = {
+  type: "delete";
+  path: string;
+};
+
+export type ApplyPatchUpdateFileOp = {
+  type: "update";
+  path: string;
+  update: string;
+  added: number;
+  deleted: number;
+};
+
+export type ApplyPatchOp =
+  | ApplyPatchCreateFileOp
+  | ApplyPatchDeleteFileOp
+  | ApplyPatchUpdateFileOp;
+
+const PATCH_PREFIX = "*** Begin Patch\n";
+const PATCH_SUFFIX = "\n*** End Patch";
+const ADD_FILE_PREFIX = "*** Add File: ";
+const DELETE_FILE_PREFIX = "*** Delete File: ";
+const UPDATE_FILE_PREFIX = "*** Update File: ";
+const END_OF_FILE_PREFIX = "*** End of File";
+const HUNK_ADD_LINE_PREFIX = "+";
+
+/**
+ * @returns null when the patch is invalid
+ */
+export function parseApplyPatch(patch: string): Array<ApplyPatchOp> | null {
+  if (!patch.startsWith(PATCH_PREFIX)) {
+    // Patch must begin with '*** Begin Patch'
+    return null;
+  } else if (!patch.endsWith(PATCH_SUFFIX)) {
+    // Patch must end with '*** End Patch'
+    return null;
+  }
+
+  const patchBody = patch.slice(
+    PATCH_PREFIX.length,
+    patch.length - PATCH_SUFFIX.length,
+  );
+
+  const lines = patchBody.split("\n");
+
+  const ops: Array<ApplyPatchOp> = [];
+
+  for (const line of lines) {
+    if (line.startsWith(END_OF_FILE_PREFIX)) {
+      continue;
+    } else if (line.startsWith(ADD_FILE_PREFIX)) {
+      ops.push({
+        type: "create",
+        path: line.slice(ADD_FILE_PREFIX.length).trim(),
+        content: "",
+      });
+      continue;
+    } else if (line.startsWith(DELETE_FILE_PREFIX)) {
+      ops.push({
+        type: "delete",
+        path: line.slice(DELETE_FILE_PREFIX.length).trim(),
+      });
+      continue;
+    } else if (line.startsWith(UPDATE_FILE_PREFIX)) {
+      ops.push({
+        type: "update",
+        path: line.slice(UPDATE_FILE_PREFIX.length).trim(),
+        update: "",
+        added: 0,
+        deleted: 0,
+      });
+      continue;
+    }
+
+    const lastOp = ops[ops.length - 1];
+
+    if (lastOp?.type === "create") {
+      lastOp.content = appendLine(
+        lastOp.content,
+        line.slice(HUNK_ADD_LINE_PREFIX.length),
+      );
+      continue;
+    }
+
+    if (lastOp?.type !== "update") {
+      // Expected update op but got ${lastOp?.type} for line ${line}
+      return null;
+    }
+
+    if (line.startsWith(HUNK_ADD_LINE_PREFIX)) {
+      lastOp.added += 1;
+    } else if (line.startsWith("-")) {
+      lastOp.deleted += 1;
+    }
+    lastOp.update += lastOp.update ? "\n" + line : line;
+  }
+
+  return ops;
+}
+
+function appendLine(content: string, line: string) {
+  if (!content.length) {
+    return line;
+  }
+  return [content, line].join("\n");
+}