feat: add read tool

[bobrykov]

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Review details

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: e75812d5-0569-447b-a3ea-aca91a60df5e

📥 Commits

Reviewing files that changed from the base of the PR and between f7f586e and d87dc0a.

📒 Files selected for processing (2)

• crates/dch-tools/src/read.rs
• crates/dch-tools/src/registry.rs

📝 Walkthrough

Walkthrough

Changes

Read tool integration

Layer / File(s)	Summary
Dependencies and path utilities Cargo.toml, crates/dch-tools/Cargo.toml, crates/dch-tools/src/util.rs	Adds shared base64 and tempfile dependencies plus MIME and HTTP(S) path helpers.
ReadTool contract and execution crates/dch-tools/src/read.rs	Adds bounded text reads, image responses, binary detection, range parsing, truncation, URL rejection, and session-history recording.
ReadTool behavioral validation crates/dch-tools/src/read.rs	Adds tests covering read behavior, parsing, content handling, history, schema, and registry properties.
Builtin registry and public wiring crates/dch-tools/src/lib.rs, crates/dch-tools/src/registry.rs	Exposes the new modules and registers ReadTool in builtin_registry.

Sequence Diagram(s)

sequenceDiagram
  participant Caller
  participant ReadTool
  participant RunnerContext
  participant FileSystem
  participant SessionState
  Caller->>ReadTool: call with file path and range options
  ReadTool->>RunnerContext: resolve path relative to cwd
  ReadTool->>FileSystem: read metadata and contents
  ReadTool->>SessionState: append FileReadEntry
  ReadTool-->>Caller: return formatted text or multipart image output

Loading

Possibly related PRs

• dch-labs/dch#3: Introduces the RunnerContext and SessionState types used by ReadTool for path resolution and read-history recording.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: adding a new read tool.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 50.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/read-tool

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[coderabbitai]

Actionable comments posted: 3

🧹 Nitpick comments (1)

crates/dch-tools/src/registry.rs (1)

9-10: 📐 Maintainability & Code Quality | 🔵 Trivial | 💤 Low value

Doc comment phrasing is slightly misleading.

"Each concrete tool registers itself here" implies tools self-register, but builtin_registry actively registers them. Consider rewording to "Each builtin tool is registered here" for clarity.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@crates/dch-tools/src/registry.rs` around lines 9 - 10, Update the doc comment
above builtin_registry to state that each builtin tool is registered here,
avoiding language that implies tools self-register. Preserve the existing
description of runner startup invocation and later task registrations.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@crates/dch-tools/src/read.rs`:
- Around line 285-291: Update the truncation logic in the read flow to check
character boundaries against shown_content, the same string later sliced by
shown_content.get(..cut), rather than the full content. Preserve the
MAX_FILE_READ_BYTES cap for partial views, and add a test covering multibyte
characters with a nonzero offset that verifies the returned content remains
truncated.
- Around line 141-156: After retrieving metadata in the read flow, validate
`metadata.is_file()` before the size check and file read. For directory paths,
return a clear `ToolOutput::error_text` message explaining that the path is a
directory and should reference a file, while preserving the existing handling
for regular files.
- Around line 396-402: Update parse_line_range so a non-empty left side with a
non-empty right side parses and validates the right endpoint, returning the
equivalent inclusive range (for example, 50:100 yields (50, 51)); retain
MAX_FILE_READ_LINES only for open-ended ranges such as 50:, and reject invalid
or non-positive endpoints consistently with the existing dash-range handling.

---

Nitpick comments:
In `@crates/dch-tools/src/registry.rs`:
- Around line 9-10: Update the doc comment above builtin_registry to state that
each builtin tool is registered here, avoiding language that implies tools
self-register. Preserve the existing description of runner startup invocation
and later task registrations.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: ec32cc07-8c7d-4824-81cb-60897d109f6d

📥 Commits

Reviewing files that changed from the base of the PR and between 265164f and f7f586e.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (6)

• Cargo.toml
• crates/dch-tools/Cargo.toml
• crates/dch-tools/src/lib.rs
• crates/dch-tools/src/read.rs
• crates/dch-tools/src/registry.rs
• crates/dch-tools/src/util.rs