Add config pipeline snapshot tests

[ryancbahan]

WHAT is this pull request doing?

Adds snapshot tests for writeAppConfigurationFile and the full config round-trip:

• Round-trip fidelity — write → read → write produces identical output (documents the existing webhook compliance reordering asymmetry, which is fixed in a later PR in this stack)
• Round-trip stabilization — verifies idempotency after the first cycle
• Mixed webhook topics — regular topics + compliance topics + include_fields
• Relative URI round-trip — verifies /webhooks paths survive the cycle unchanged
• Webhook edge cases — same URI with different filter values, same URI with different include_fields, mixed topics + compliance_topics on a single subscription

No production code changes. Purely additive test file.

WHY are these changes introduced?

The config pipeline (write → read → write round-trip) has no CLI command that exercises it end-to-end — app deploy reads config but doesn't write it back, and app config link writes but doesn't round-trip. This means there's no natural place to add e2e tests for config read/write regressions. Unit-level snapshot tests are the right tool here because:

1. No CLI command does a clean round-trip. An e2e test would need to orchestrate multiple commands and diff file output, adding complexity without additional signal over calling the pipeline functions directly. (Maybe we get here later)
2. Snapshot diffs are precise. When a change alters TOML output (field ordering, whitespace, section headers), the snapshot diff shows exactly what changed, making review trivial. An e2e test would need custom diffing logic to achieve the same clarity.
3. Fast feedback loop. These run in ~30ms total vs minutes for e2e. During refactoring (path extraction, transform extraction, webhook merging changes), fast iteration matters.
4. They test the actual pipeline functions (writeAppConfigurationFile + parseConfigurationFile) — the same code paths that every CLI command uses. No mocking, no indirection.

How to test your changes?

npx vitest run packages/app/src/cli/services/app/config-pipeline-snapshot.test.ts

Measuring impact

• n/a - this doesn't need measurement, e.g. a linting rule or a bug-fix

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes

[ryancbahan]

• Add declaredKeys property to extension specifications #6980
• Remove dead defaultAppConfigReverseTransform and add round-trip fidelity tests #6953
• Extract mergeAllWebhooks transform from Zod schema into breakdown-extensions #6952
• Extract scopes transforms from Zod schemas into accessor functions #6951
• Extract extension_directories transforms from Zod schema #6950
• Extract path from AppConfiguration into App.configPath #6949
• Add config pipeline snapshot tests #6947 👈 (View in Graphite)
• Rename extension-to-toml → extension-config-builder #6945
• Migrate all TOML I/O callsites to TomlFile #6944
• Introduce TomlFile abstraction for TOML file I/O #6943
• main

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[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	79.23%	14599/18426
🟡	Branches	73.49%	7249/9864
🟡	Functions	79.37%	3717/4683
🟡	Lines	79.56%	13795/17339

Test suite run success

3830 tests passing in 1466 suites.

Report generated by 🧪jest coverage report action from a29ba87

[github-actions]

Differences in type declarations

We detected differences in the type declarations generated by Typescript for this branch compared to the baseline ('main' branch). Please, review them to ensure they are backward-compatible. Here are some important things to keep in mind:

• Some seemingly private modules might be re-exported through public modules.
• If the branch is behind main you might see odd diffs, rebase main into this branch.

New type declarations

packages/cli-kit/dist/public/node/toml/codec.d.ts

import { JsonMap } from '../../../private/common/json.js';
export type JsonMapType = JsonMap;
/**
 * Given a TOML string, it returns a JSON object.
 *
 * @param input - TOML string.
 * @returns JSON object.
 */
export declare function decodeToml(input: string): JsonMapType;
/**
 * Given a JSON object, it returns a TOML string.
 *
 * @param content - JSON object.
 * @returns TOML string.
 */
export declare function encodeToml(content: JsonMap | object): string;

packages/cli-kit/dist/public/node/toml/index.d.ts

export type { JsonMapType } from './codec.js';

packages/cli-kit/dist/public/node/toml/toml-file.d.ts

import { JsonMapType } from './codec.js';
/**
 * Thrown when a TOML file cannot be parsed. Includes the file path for context.
 */
export declare class TomlParseError extends Error {
    readonly path: string;
    constructor(path: string, cause: Error);
}
/**
 * General-purpose TOML file abstraction.
 *
 * Provides a unified interface for reading, patching, removing keys from, and replacing
 * the content of TOML files on disk.
 *
 * - `read` populates content from disk
 * - `patch` does surgical WASM-based edits (preserves comments and formatting)
 * - `remove` deletes a key by dotted path (preserves comments and formatting)
 * - `replace` does a full re-serialization (comments and formatting are NOT preserved).
 * - `transformRaw` applies a function to the raw TOML string on disk.
 */
export declare class TomlFile {
    /**
     * Read and parse a TOML file from disk. Throws if the file doesn't exist or contains invalid TOML.
     * Parse errors are wrapped in {@link TomlParseError} with the file path for context.
     *
     * @param path - Absolute path to the TOML file.
     * @returns A TomlFile instance with parsed content.
     */
    static read(path: string): Promise<TomlFile>;
    readonly path: string;
    content: JsonMapType;
    constructor(path: string, content: JsonMapType);
    /**
     * Surgically patch values in the TOML file, preserving comments and formatting.
     *
     * Accepts a nested object whose leaf values are set in the TOML. Intermediate tables are
     * created automatically. Setting a leaf to `undefined` removes it (use `remove()` for a
     * clearer API when deleting keys).
     *
     * @example
     * ```ts
     * await file.patch({build: {dev_store_url: 'my-store.myshopify.com'}})
     * await file.patch({application_url: 'https://example.com', auth: {redirect_urls: ['...']}})
     * ```
     */
    patch(changes: {
        [key: string]: unknown;
    }): Promise<void>;
    /**
     * Remove a key from the TOML file by dotted path, preserving comments and formatting.
     *
     * @param keyPath - Dotted key path to remove (e.g. 'build.include_config_on_deploy').
     * @example
     * ```ts
     * await file.remove('build.include_config_on_deploy')
     * ```
     */
    remove(keyPath: string): Promise<void>;
    /**
     * Replace the entire file content. The file is fully re-serialized — comments and formatting
     * are NOT preserved.
     *
     * @param content - The new content to write.
     * @example
     * ```ts
     * await file.replace({client_id: 'abc', name: 'My App'})
     * ```
     */
    replace(content: JsonMapType): Promise<void>;
    /**
     * Transform the raw TOML string on disk. Reads the file, applies the transform function
     * to the raw text, writes back, and re-parses to keep `content` in sync.
     *
     * Use this for text-level operations that can't be expressed as structured edits —
     * e.g. Injecting comments or positional insertion of keys in arrays-of-tables.
     * Subsequent `patch()` calls will preserve any comments added this way.
     *
     * @param transform - A function that receives the raw TOML string and returns the modified string.
     * @example
     * ```ts
     * await file.transformRaw((raw) => `# Header comment\n${raw}`)
     * ```
     */
    transformRaw(transform: (raw: string) => string): Promise<void>;
    private decode;
}

Existing type declarations

We found no diffs with existing type declarations

[github-actions]

We detected some changes at packages/*/src and there are no updates in the .changeset.
If the changes are user-facing, run pnpm changeset add to track your changes and include them in the next release CHANGELOG.

Caution

DO NOT create changesets for features which you do not wish to be included in the public changelog of the next CLI release.