--- title: "postcss-selector-parser Breaking Changes on npm | Since.dev" description: "What each postcss-selector-parser release removed, renamed or changed: 19 breaking changes in 8 versions on npm, each with its source." canonical_url: https://since.dev/packages/npm/postcss-selector-parser last_updated: 2026-10-19 --- # postcss-selector-parser breaking changes Every breaking API change we have recorded in postcss-selector-parser on npm: 19 breaking changes in 8 versions. Below are its newest 6 versions, removals and renames first, each with its source. Newest change October 19, 2026 ## 7.1.2 1 breaking change, first published June 9, 2026. - **Signature changed** `Base.toString` Was toString(): string; now toString(options?: StringifyOptions): string. [npmjs.com](https://www.npmjs.com/package/postcss-selector-parser/v/7.1.2) ## 6.1.5 1 breaking change, first published October 19, 2026. - **Configuration changed** The 6.x line now receives only security fixes, with no features, other bug fixes or type changes. Users who want continued development should move to 7.x; 6.1.5 is published under the legacy-v6 dist-tag so plain npm install resolves to 7.x. [github.com](https://github.com/postcss/postcss-selector-parser/releases/tag/6.1.5) ## 6.1.3 4 breaking changes, first published June 11, 2026. - **Behavior changed** `insertAfter` Inserting nodes while iterating a container with each now changes the next callback position, so code relying on the old visiting order must be updated. [github.com](https://github.com/postcss/postcss-selector-parser/commit/4fa6e860a176985e03fda969b2b435fe168f31c2) - **Behavior changed** `insertBefore` Inserting nodes while iterating a container with each now changes the next callback position, so code relying on the old visiting order must be updated. [github.com](https://github.com/postcss/postcss-selector-parser/commit/4fa6e860a176985e03fda969b2b435fe168f31c2) - **Behavior changed** `prepend` Inserting nodes while iterating a container with each now changes the next callback position, so code relying on the old visiting order must be updated. [github.com](https://github.com/postcss/postcss-selector-parser/commit/4fa6e860a176985e03fda969b2b435fe168f31c2) - **Signature changed** `Base.toString` Was toString(): string; now toString(options?: StringifyOptions): string. [npmjs.com](https://www.npmjs.com/package/postcss-selector-parser/v/6.1.3) ## 6.1.1 3 breaking changes, first published July 11, 2024. - **Signature changed** `id` Was function id(opts: any): any; now function id(opts: any): Identifier. [npmjs.com](https://www.npmjs.com/package/postcss-selector-parser/v/6.1.1) - **Signature changed** `nesting` Was function nesting(opts: any): any; now function nesting(opts?: any): Nesting. [npmjs.com](https://www.npmjs.com/package/postcss-selector-parser/v/6.1.1) - **Signature changed** `universal` Was function universal(opts?: NamespaceOptions): any; now function universal(opts?: NamespaceOptions): Universal. [npmjs.com](https://www.npmjs.com/package/postcss-selector-parser/v/6.1.1) ## 6.0.16 2 breaking changes, first published March 13, 2024. - **Signature changed** `Container.each` Was each(callback: (node: Child) => boolean | void): boolean | undefined; now each(callback: (node: Child, index: number) => boolean | void): boolean | undefined. [npmjs.com](https://www.npmjs.com/package/postcss-selector-parser/v/6.0.16) - **Signature changed** `Container.walk` Was walk(callback: (node: Node) => boolean | void): boolean | undefined; now walk(callback: (node: Node, index: number) => boolean | void): boolean | undefined. [npmjs.com](https://www.npmjs.com/package/postcss-selector-parser/v/6.0.16) ## 6.0.15 2 breaking changes, first published December 29, 2023. - **Signature changed** `Base.next` Was next(): Node; now next(): Node | undefined. [npmjs.com](https://www.npmjs.com/package/postcss-selector-parser/v/6.0.15) - **Signature changed** `Base.prev` Was prev(): Node; now prev(): Node | undefined. [npmjs.com](https://www.npmjs.com/package/postcss-selector-parser/v/6.0.15) ## Check your code These are the changes. To see which of them reach your code, [scan a public repository](https://since.dev/scan.md), or have your coding agent call `check_code` with your manifest or lockfile over [MCP](https://since.dev/docs.md#mcp). [The API](https://since.dev/docs.md#api) reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys. ## Put your code on continuous management. Scan a public repository now, or give your agent one line. ### See how out of date your code is. [Scan a repository](https://since.dev/scan.md). Any public GitHub repository. No sign-in. ### Tell your agent what changed since it was trained. `claude mcp add --transport http since https://api.since.dev/mcp` --- Every page on this site as Markdown: https://since.dev/sitemap.md. For agents: https://since.dev/llms.txt.