[NopeCharon]

Closes #21

Summary

Adds a read-only mode. When it's on, a client sends only GET, HEAD and OPTIONS requests. Any request that could create, change or delete something fails with forges.ErrReadOnly, and nothing reaches the forge.

Library:

hc := forges.ReadOnlyHTTPClient(nil)
client := forges.NewClient(
    forges.WithHTTPClient(hc),
    forges.WithForge("github.com", github.New(token, hc)),
)
// f.Issues().Create(...) now returns an error where errors.Is(err, forges.ErrReadOnly) is true

CLI:

FORGE_READ_ONLY=true forge issue list
forge --read-only label create bug
# Error: create label: Post "https://…/labels": write refused in read-only mode

Why a transport

All backend constructors already take an *http.Client, so the check is a RoundTripper that refuses unsafe methods. That works the same for every backend and every operation, including ones added later, and needs no per-service wrapper to keep up with the interfaces. None of the backends use POST for reads (no GraphQL, and the Gerrit and Bitbucket POSTs are all writes), so reads keep working. Each SDK keeps the error chain, so errors.Is works for GitHub, GitLab, Gitea/Forgejo, Bitbucket and Gerrit. GitLab's retry policy doesn't retry the refused request.

Behaviour

• ReadOnlyHTTPClient(hc) returns a copy of hc, so the caller's client isn't changed. A nil hc copies http.DefaultClient. A refused request's body is closed, as the RoundTripper contract requires.
• --read-only / FORGE_READ_ONLY: the value is parsed with strconv.ParseBool. The flag takes precedence, so --read-only=false overrides FORGE_READ_ONLY=true. Anything that doesn't parse, such as FORGE_READ_ONLY=maybe, is an error rather than being silently ignored.
• forge api goes through the same client, so forge api -X POST … is refused too.
• pr create --push is refused before anything happens. Otherwise the branch would be pushed first and only then would the PR request be refused.

Details

• Detected forges: newClientForBaseURL now passes the shared client to forges.Client with WithHTTPClient. Before this, a self-hosted forge found by probing was built with a nil client and used http.DefaultClient, which would have skipped read-only mode. Refuse HTTPS to HTTP redirects in the shared HTTP client #200 needs the same line for its redirect policy, so whichever PR merges second will have a one-line conflict.
• Test helper: resetCmd now clears slice flags with Replace(nil). Set("[]") was adding "[]" as an element, which broke forge api when a test ran it through rootCmd.

Tests

• readonly_test.go: the four allowed methods (counting the empty method, which net/http treats as GET) go through. POST, PUT, PATCH, DELETE, CONNECT, TRACE and an extension method are refused without reaching the server, and their bodies are closed. Also checks that the caller's client isn't changed and that a nil client is handled.
• {github,gitlab,gitea,bitbucket,gerrit}/readonly_test.go: each builds the backend with its exported constructor and a read-only client. A read succeeds, and two writes return ErrReadOnly without the server seeing them.
• internal/cli/readonly_test.go: runs the real command against a fake Gitea server to cover the flag, the environment variable, both override directions, an invalid value, forge api -X POST, a forge found by detection, and pr create --push. The detected-forge case fails without the WithHTTPClient change, and the --push case fails without the up-front check because the push is attempted.

go test -race ./..., go test -tags=tinygo ./gitlab, the js/wasm and wasip1 builds and golangci-lint v2.14.0 all pass.

Summary by CodeRabbit

• New Features
  • Added a CLI read-only mode, enabled with --read-only or FORGE_READ_ONLY=true. It permits GET, HEAD, and OPTIONS requests and rejects writes before they are sent. The flag can override the environment setting for a command.
  • Added a reusable read-only HTTP client for library integrations. Write attempts are rejected with a read-only error.
  • pr create --push is rejected in read-only mode before a push occurs.
• Documentation
  • Added guidance on enabling CLI read-only mode and using the read-only HTTP client.

[coderabbitai]

No actionable comments were generated in the recent review.

Walkthrough

The change adds a reusable read-only HTTP client and CLI controls for enabling it. The client permits empty, GET, HEAD, and OPTIONS methods and rejects other methods. CLI tests cover flag and environment settings, write commands, API requests, and pr create --push.

Changes: Read-only mode

Layer / File(s)	Summary
HTTP read-only contract forge.go, readonly.go, readonly_test.go, bitbucket/readonly_test.go, gerrit/readonly_test.go, gitea/readonly_test.go, github/readonly_test.go, gitlab/readonly_test.go, README.md	Adds ErrReadOnly and ReadOnlyHTTPClient. Tests check permitted methods, rejected methods, request-body closure, client copying, and read-only behavior across backends. The README documents library usage.
CLI configuration and enforcement internal/cli/root.go, internal/resolve/transport.go, internal/resolve/resolve.go, internal/cli/pr.go, internal/cli/readonly_test.go, internal/cli/auth_test.go, README.md	Adds the --read-only flag and FORGE_READ_ONLY handling, applies the wrapper to resolved forge clients, and rejects pr create --push in read-only mode. CLI tests cover mode selection, write requests, and overrides. The README documents CLI usage.

Estimated code review effort: 3 (Moderate) | ~25 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant CLI
  participant Resolve
  participant ForgeHTTPClient
  participant ForgeBackend
  CLI->>Resolve: set read-only mode from flag or environment
  Resolve->>ForgeHTTPClient: build shared HTTP client
  ForgeHTTPClient->>ForgeHTTPClient: wrap client when read-only is enabled
  ForgeBackend->>ForgeHTTPClient: send API request
  ForgeHTTPClient-->>ForgeBackend: forward allowed method or return ErrReadOnly

Loading

Possibly related PRs

• git-pkgs/forge#204: Adds forge construction and first-use detection. This PR applies read-only behavior through the shared client used by detected forges.
• git-pkgs/forge#203: Adds --fill to pr create. The two changes affect control flow in the same command when --fill and --push are used.

Suggested reviewers: abhinavgautam01, andrew

Merge Risk: Minimal · up to 08cc2

This adds a read-only mode that refuses write requests with a clear error. The supplied evidence shows no merge-blocking risk.

Security architecture risk: Low · up to 08cc2

The design centralizes request filtering and blocks PR pushes before side effects. No introduced security defect was established. This remains an opt-in client-side safeguard, not a replacement for restricted token permissions.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The control's scope is the participating client, not one repository or tenant: its method decision applies regardless of destination URL. Permitted requests retain existing credential authority, and callers that do not opt in remain outside the library guarantee.

Trust Boundaries and Controls

• observed — HTTP enforcement and Git-push enforcement are distinct controls. The PR command rejects --push as its first execution step, before the push-and-create sequence; relying solely on the HTTP transport would not cover that Git operation.

Resilience and Maintainability Implications

• inferred — For the inspected single-command lifecycle, policy setup precedes client construction and the early push refusal prevents partial remote mutation through the push-and-create sequence. Refused HTTP requests have no remote rollback requirement because they never reach the underlying transport. Concurrent reconfiguration would require separate lifecycle guarantees; the current resolver setting is unsynchronized and clients retain construction-time policy.

Hardening Proposals

• proposed — For CI and audit deployments, pair this safeguard with forge-enforced read-only credentials and document that it is a method filter rather than credential isolation or a semantic authorization layer. This reduces dependence on every caller opting in and every allowed endpoint being non-mutating.

Pre-merge checks: 4

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title "Add read-only mode for the library and CLI" matches the main change. The changeset adds a read-only HTTP client (readonly.go, ErrReadOnly in forge.go), a --read-only flag with FORGE_READ_ON…
Linked Issues check		Issue #21 requires a client mode that prevents write operations and returns a clear error. The only active direct link is #21. The reviewed head implements this in readonly.go. ReadOnlyHTTPClient …
Out of Scope Changes check		Each changed area supports read-only mode. These areas are: readonly.go and its tests; ErrReadOnly in forge.go; per-backend read-only tests; CLI flag and environment handling in `internal/cli/ro…

Full details: Title check

Explanation

The title "Add read-only mode for the library and CLI" matches the main change. The changeset adds a read-only HTTP client (readonly.go, ErrReadOnly in forge.go), a --read-only flag with FORGE_READ_ONLY environment handling in internal/cli/root.go, and tests for each backend. The title is short, specific, and names both the library and CLI surfaces.

Full details: Linked Issues check

Explanation

Issue #21 requires a client mode that prevents write operations and returns a clear error. The only active direct link is #21. The reviewed head implements this in readonly.go. ReadOnlyHTTPClient returns a copy of the client. Its readOnlyTransport forwards only the empty method, GET, HEAD and OPTIONS. Other methods close the request body and return ErrReadOnly before any request is sent. The PR adds readonly_test.go for the transport. It also adds per-backend tests for GitHub, GitLab, Gitea, Bitbucket and Gerrit. Those tests check that reads succeed and that writes return ErrReadOnly without reaching the server. The CLI also exposes the mode through --read-only and FORGE_READ_ONLY. All coding requirements of #21 are met.

Full details: Out of Scope Changes check

Explanation

Each changed area supports read-only mode. These areas are: readonly.go and its tests; ErrReadOnly in forge.go; per-backend read-only tests; CLI flag and environment handling in internal/cli/root.go; resolve.SetReadOnly and the shared client in internal/resolve/transport.go and resolve.go; the pr create --push guard in internal/cli/pr.go; CLI tests in internal/cli/readonly_test.go; the resetCmd slice-flag fix in internal/cli/auth_test.go, which the CLI tests need; and README documentation. The resetCmd change is a test-helper fix that the new CLI tests depend on. No unrelated work was found in the summary.

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Commits

Reviewing files that changed from the base of the PR and between 8f624ce and 08cc252.

Files selected for processing: 4

• README.md
• forge.go
• internal/resolve/resolve.go
• internal/resolve/transport.go

Files skipped from review as they are similar to previous changes: 1

• internal/resolve/resolve.go

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[coderabbitai]

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only still-valid issues, skip the rest with a brief reason, keep changes
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Write docstrings for the functions missing them to satisfy the coverage
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Run configuration

• Source mode: Auto
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• Branch: Unavailable
• File: No configuration file from this repository applied
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• Run ID: e1ce041b-e96a-45b1-b3cc-4bdb16a391df

Commits

Reviewing files that changed from the base of the PR and between 7f214f9 and 8f624ce.

Files selected for processing: 15

• README.md
• bitbucket/readonly_test.go
• forge.go
• gerrit/readonly_test.go
• gitea/readonly_test.go
• github/readonly_test.go
• gitlab/readonly_test.go
• internal/cli/auth_test.go
• internal/cli/pr.go
• internal/cli/readonly_test.go
• internal/cli/root.go
• internal/resolve/resolve.go
• internal/resolve/transport.go
• readonly.go
• readonly_test.go

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