84 lines
2.8 KiB
JavaScript
84 lines
2.8 KiB
JavaScript
function splitNulFields(buffer, options = {}) {
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if (!Buffer.isBuffer(buffer)) {
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throw new Error("Raw Git diff must be provided as a Buffer.");
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}
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if (buffer.length === 0 && options.allowEmpty) {
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return [];
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}
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if (buffer.length === 0 || buffer[buffer.length - 1] !== 0) {
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throw new Error("Raw Git diff is empty or missing its final NUL terminator.");
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}
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const fields = [];
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let start = 0;
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for (let index = 0; index < buffer.length; index += 1) {
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if (buffer[index] === 0) {
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fields.push(buffer.subarray(start, index));
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start = index + 1;
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}
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}
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return fields;
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}
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function decodeGitPath(buffer) {
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let value;
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try {
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value = new TextDecoder("utf-8", { fatal: true }).decode(buffer);
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} catch {
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throw new Error("Raw Git diff contains a path that is not canonical UTF-8.");
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}
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if (Buffer.from(value, "utf8").compare(buffer) !== 0) {
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throw new Error("Raw Git diff path did not round-trip to canonical UTF-8 bytes.");
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}
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return value;
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}
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function parseRawDiff(buffer, options = {}) {
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const fields = splitNulFields(buffer, options);
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if (!fields.length) return [];
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const records = [];
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for (let index = 0; index < fields.length;) {
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const header = fields[index].toString("ascii");
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if (!fields[index].equals(Buffer.from(header, "ascii"))) {
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throw new Error("Raw Git diff contains a non-ASCII record header.");
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}
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index += 1;
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const match = header.match(
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/^:(?<oldMode>[0-7]{6}) (?<newMode>[0-7]{6}) (?<oldOid>[0-9a-f]{40}|[0-9a-f]{64}) (?<newOid>[0-9a-f]{40}|[0-9a-f]{64}) (?<status>[ACDMRTUXB])(?<score>[0-9]{0,3})$/u,
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);
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if (!match?.groups || match.groups.oldOid.length !== match.groups.newOid.length) {
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throw new Error(`Malformed raw Git diff header: ${header}`);
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}
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if (index >= fields.length) throw new Error("Raw Git diff record is missing its path.");
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const firstPath = decodeGitPath(fields[index]);
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index += 1;
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const isRenameOrCopy = match.groups.status === "R" || match.groups.status === "C";
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let secondPath = null;
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if (isRenameOrCopy) {
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if (index >= fields.length) {
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throw new Error("Raw Git rename/copy record is missing its destination path.");
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}
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secondPath = decodeGitPath(fields[index]);
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index += 1;
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}
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const status = match.groups.status;
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records.push({
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status,
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old_path: status === "A" ? null : firstPath,
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new_path: status === "D" ? null : isRenameOrCopy ? secondPath : firstPath,
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old_mode: match.groups.oldMode,
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new_mode: match.groups.newMode,
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old_oid: match.groups.oldOid,
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new_oid: match.groups.newOid,
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similarity: match.groups.score ? Number(match.groups.score) : null,
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});
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}
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return records;
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}
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module.exports = { decodeGitPath, parseRawDiff, splitNulFields };
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