import { describe, expect } from "bun:test"

import path from "path"

import * as fs from "fs/promises"

import { LayerNode } from "@opencode-ai/core/effect/layer-node"

import { Cause, Effect, Exit, Layer } from "effect"

import { ApplyPatchTool } from "../../src/tool/apply_patch"

import { LSP } from "@/lsp/lsp"

import { FSUtil } from "@opencode-ai/core/fs-util"

import { Format } from "../../src/format"

import { Agent } from "../../src/agent/agent"

import { EventV2Bridge } from "../../src/event-v2-bridge"

import { Truncate } from "@/tool/truncate"

import { TestInstance } from "../fixture/fixture"

import { SessionID, MessageID } from "../../src/session/schema"

import { testEffect } from "../lib/effect"

const it = testEffect(

LayerNode.compile(

LayerNode.group([LSP.node, FSUtil.node, Format.node, EventV2Bridge.node, Truncate.node, Agent.node]),

),

)

const baseCtx = {

sessionID: SessionID.make("ses_test"),

messageID: MessageID.make("msg_test"),

callID: "",

agent: "build",

abort: AbortSignal.any([]),

messages: [],

metadata: () => Effect.void,

}

type AskInput = {

permission: string

patterns: string[]

always: string[]

metadata: {

diff: string

filepath: string

files: Array<{

filePath: string

relativePath: string

type: "add" | "update" | "delete" | "move"

patch: string

additions: number

deletions: number

movePath?: string

}>

}

}

type ToolCtx = typeof baseCtx & {

ask: (input: AskInput) => Effect.Effect<void>

}

const execute = Effect.fn("ApplyPatchToolTest.execute")(function* (params: { patchText: string }, ctx: ToolCtx) {

const info = yield* ApplyPatchTool

const tool = yield* info.init()

return yield* tool.execute(params, ctx)

})

const makeCtx = () => {

const calls: AskInput[] = []

const ctx: ToolCtx = {

...baseCtx,

ask: (input) =>

Effect.sync(() => {

calls.push(input)

}),

}

return { ctx, calls }

}

const readText = (filepath: string) => Effect.promise(() => fs.readFile(filepath, "utf-8"))

const writeText = (filepath: string, content: string) => Effect.promise(() => fs.writeFile(filepath, content, "utf-8"))

const makeDir = (dir: string) => Effect.promise(() => fs.mkdir(dir, { recursive: true }))

const expectFailure = <A, E, R>(effect: Effect.Effect<A, E, R>, message?: string) =>

Effect.gen(function* () {

const exit = yield* Effect.exit(effect)

expect(Exit.isFailure(exit)).toBe(true)

if (Exit.isFailure(exit) && message) expect(Cause.pretty(exit.cause)).toContain(message)

})

const expectReadFailure = (filepath: string) => expectFailure(readText(filepath))

describe("tool.apply_patch freeform", () => {

it.live("requires patchText", () =>

Effect.gen(function* () {

const { ctx } = makeCtx()

yield* expectFailure(execute({ patchText: "" }, ctx), "patchText is required")

}),

)

it.live("rejects invalid patch format", () =>

Effect.gen(function* () {

const { ctx } = makeCtx()

yield* expectFailure(execute({ patchText: "invalid patch" }, ctx), "apply_patch verification failed")

}),

)

it.live("rejects empty patch", () =>

Effect.gen(function* () {

const { ctx } = makeCtx()

yield* expectFailure(execute({ patchText: "*** Begin Patch\n*** End Patch" }, ctx), "patch rejected: empty patch")

}),

)

it.instance(

"applies add/update/delete in one patch",

() =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx, calls } = makeCtx()

const modifyPath = path.join(test.directory, "modify.txt")

const deletePath = path.join(test.directory, "delete.txt")

yield* writeText(modifyPath, "line1\nline2\n")

yield* writeText(deletePath, "obsolete\n")

const patchText =

"*** Begin Patch\n*** Add File: nested/new.txt\n+created\n*** Delete File: delete.txt\n*** Update File: modify.txt\n@@\n-line2\n+changed\n*** End Patch"

const result = yield* execute({ patchText }, ctx)

expect(result.title).toContain("Success. Updated the following files")

expect(result.output).toContain("Success. Updated the following files")

// Strict formatting assertions for slashes

expect(result.output).toMatch(/A nested\/new\.txt/)

expect(result.output).toMatch(/D delete\.txt/)

expect(result.output).toMatch(/M modify\.txt/)

if (process.platform === "win32") {

expect(result.output).not.toContain("\\")

}

expect(result.metadata.diff).toContain("Index:")

expect(calls.length).toBe(1)

// Verify permission metadata includes files array for UI rendering

const permissionCall = calls[0]

expect(permissionCall.metadata.files).toHaveLength(3)

expect(permissionCall.metadata.files.map((f) => f.type).sort()).toEqual(["add", "delete", "update"])

const addFile = permissionCall.metadata.files.find((f) => f.type === "add")

expect(addFile?.relativePath).toBe("nested/new.txt")

expect(addFile?.patch).toContain("+created")

const updateFile = permissionCall.metadata.files.find((f) => f.type === "update")

expect(updateFile?.patch).toContain("-line2")

expect(updateFile?.patch).toContain("+changed")

expect(yield* readText(path.join(test.directory, "nested", "new.txt"))).toBe("created\n")

expect(yield* readText(modifyPath)).toBe("line1\nchanged\n")

yield* expectReadFailure(deletePath)

}),

{ git: true },

)

it.instance(

"permission metadata includes move file info",

() =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx, calls } = makeCtx()

const original = path.join(test.directory, "old", "name.txt")

yield* makeDir(path.dirname(original))

yield* writeText(original, "old content\n")

const patchText =

"*** Begin Patch\n*** Update File: old/name.txt\n*** Move to: renamed/dir/name.txt\n@@\n-old content\n+new content\n*** End Patch"

yield* execute({ patchText }, ctx)

expect(calls.length).toBe(1)

const permissionCall = calls[0]

expect(permissionCall.metadata.files).toHaveLength(1)

const moveFile = permissionCall.metadata.files[0]

expect(moveFile.type).toBe("move")

expect(moveFile.relativePath).toBe("renamed/dir/name.txt")

expect(moveFile.movePath).toBe(path.join(test.directory, "renamed/dir/name.txt"))

expect(moveFile.patch).toContain("-old content")

expect(moveFile.patch).toContain("+new content")

}),

{ git: true },

)

it.instance("applies multiple hunks to one file", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "multi.txt")

yield* writeText(target, "line1\nline2\nline3\nline4\n")

const patchText =

"*** Begin Patch\n*** Update File: multi.txt\n@@\n-line2\n+changed2\n@@\n-line4\n+changed4\n*** End Patch"

yield* execute({ patchText }, ctx)

expect(yield* readText(target)).toBe("line1\nchanged2\nline3\nchanged4\n")

}),

)

it.instance("does not invent a first-line diff for BOM files", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx, calls } = makeCtx()

const bom = String.fromCharCode(0xfeff)

const target = path.join(test.directory, "example.cs")

yield* writeText(target, `${bom}using System;\n\nclass Test {}\n`)

const patchText =

"*** Begin Patch\n*** Update File: example.cs\n@@\n class Test {}\n+class Next {}\n*** End Patch"

yield* execute({ patchText }, ctx)

expect(calls.length).toBe(1)

const shown = calls[0].metadata.files[0]?.patch ?? ""

expect(shown).not.toContain(bom)

expect(shown).not.toContain("-using System;")

expect(shown).not.toContain("+using System;")

const content = yield* readText(target)

expect(content.charCodeAt(0)).toBe(0xfeff)

expect(content.slice(1)).toBe("using System;\n\nclass Test {}\nclass Next {}\n")

}),

)

it.instance("inserts lines with insert-only hunk", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "insert_only.txt")

yield* writeText(target, "alpha\nomega\n")

const patchText = "*** Begin Patch\n*** Update File: insert_only.txt\n@@\n alpha\n+beta\n omega\n*** End Patch"

yield* execute({ patchText }, ctx)

expect(yield* readText(target)).toBe("alpha\nbeta\nomega\n")

}),

)

it.instance("appends trailing newline on update", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "no_newline.txt")

yield* writeText(target, "no newline at end")

const patchText =

"*** Begin Patch\n*** Update File: no_newline.txt\n@@\n-no newline at end\n+first line\n+second line\n*** End Patch"

yield* execute({ patchText }, ctx)

const contents = yield* readText(target)

expect(contents.endsWith("\n")).toBe(true)

expect(contents).toBe("first line\nsecond line\n")

}),

)

it.instance("moves file to a new directory", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const original = path.join(test.directory, "old", "name.txt")

yield* makeDir(path.dirname(original))

yield* writeText(original, "old content\n")

const patchText =

"*** Begin Patch\n*** Update File: old/name.txt\n*** Move to: renamed/dir/name.txt\n@@\n-old content\n+new content\n*** End Patch"

yield* execute({ patchText }, ctx)

const moved = path.join(test.directory, "renamed", "dir", "name.txt")

yield* expectReadFailure(original)

expect(yield* readText(moved)).toBe("new content\n")

}),

)

it.instance("moves file overwriting existing destination", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const original = path.join(test.directory, "old", "name.txt")

const destination = path.join(test.directory, "renamed", "dir", "name.txt")

yield* makeDir(path.dirname(original))

yield* makeDir(path.dirname(destination))

yield* writeText(original, "from\n")

yield* writeText(destination, "existing\n")

const patchText =

"*** Begin Patch\n*** Update File: old/name.txt\n*** Move to: renamed/dir/name.txt\n@@\n-from\n+new\n*** End Patch"

yield* execute({ patchText }, ctx)

yield* expectReadFailure(original)

expect(yield* readText(destination)).toBe("new\n")

}),

)

it.instance("adds file overwriting existing file", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "duplicate.txt")

yield* writeText(target, "old content\n")

const patchText = "*** Begin Patch\n*** Add File: duplicate.txt\n+new content\n*** End Patch"

yield* execute({ patchText }, ctx)

expect(yield* readText(target)).toBe("new content\n")

}),

)

it.instance("rejects update when target file is missing", () =>

Effect.gen(function* () {

const { ctx } = makeCtx()

const patchText = "*** Begin Patch\n*** Update File: missing.txt\n@@\n-nope\n+better\n*** End Patch"

yield* expectFailure(

execute({ patchText }, ctx),

"apply_patch verification failed: Failed to read file to update",

)

}),

)

it.instance("rejects delete when file is missing", () =>

Effect.gen(function* () {

const { ctx } = makeCtx()

const patchText = "*** Begin Patch\n*** Delete File: missing.txt\n*** End Patch"

yield* expectFailure(execute({ patchText }, ctx))

}),

)

it.instance("rejects delete when target is a directory", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const dirPath = path.join(test.directory, "dir")

yield* makeDir(dirPath)

const patchText = "*** Begin Patch\n*** Delete File: dir\n*** End Patch"

yield* expectFailure(execute({ patchText }, ctx))

}),

)

it.instance("rejects invalid hunk header", () =>

Effect.gen(function* () {

const { ctx } = makeCtx()

const patchText = "*** Begin Patch\n*** Frobnicate File: foo\n*** End Patch"

yield* expectFailure(execute({ patchText }, ctx), "apply_patch verification failed")

}),

)

it.instance("rejects update with missing context", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "modify.txt")

yield* writeText(target, "line1\nline2\n")

const patchText = "*** Begin Patch\n*** Update File: modify.txt\n@@\n-missing\n+changed\n*** End Patch"

yield* expectFailure(execute({ patchText }, ctx), "apply_patch verification failed")

expect(yield* readText(target)).toBe("line1\nline2\n")

}),

)

it.instance("verification failure leaves no side effects", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const patchText =

"*** Begin Patch\n*** Add File: created.txt\n+hello\n*** Update File: missing.txt\n@@\n-old\n+new\n*** End Patch"

yield* expectFailure(execute({ patchText }, ctx))

yield* expectReadFailure(path.join(test.directory, "created.txt"))

}),

)

it.instance("supports end of file anchor", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "tail.txt")

yield* writeText(target, "alpha\nlast\n")

const patchText = "*** Begin Patch\n*** Update File: tail.txt\n@@\n-last\n+end\n*** End of File\n*** End Patch"

yield* execute({ patchText }, ctx)

expect(yield* readText(target)).toBe("alpha\nend\n")

}),

)

it.instance("rejects missing second chunk context", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "two_chunks.txt")

yield* writeText(target, "a\nb\nc\nd\n")

const patchText = "*** Begin Patch\n*** Update File: two_chunks.txt\n@@\n-b\n+B\n\n-d\n+D\n*** End Patch"

yield* expectFailure(execute({ patchText }, ctx))

expect(yield* readText(target)).toBe("a\nb\nc\nd\n")

}),

)

it.instance("disambiguates change context with @@ header", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "multi_ctx.txt")

yield* writeText(target, "fn a\nx=10\ny=2\nfn b\nx=10\ny=20\n")

const patchText = "*** Begin Patch\n*** Update File: multi_ctx.txt\n@@ fn b\n-x=10\n+x=11\n*** End Patch"

yield* execute({ patchText }, ctx)

expect(yield* readText(target)).toBe("fn a\nx=10\ny=2\nfn b\nx=11\ny=20\n")

}),

)

it.instance("EOF anchor matches from end of file first", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "eof_anchor.txt")

// File has duplicate "marker" lines - one in middle, one at end

yield* writeText(target, "start\nmarker\nmiddle\nmarker\nend\n")

// With EOF anchor, should match the LAST "marker" line, not the first

const patchText =

"*** Begin Patch\n*** Update File: eof_anchor.txt\n@@\n-marker\n-end\n+marker-changed\n+end\n*** End of File\n*** End Patch"

yield* execute({ patchText }, ctx)

// First marker unchanged, second marker changed

expect(yield* readText(target)).toBe("start\nmarker\nmiddle\nmarker-changed\nend\n")

}),

)

it.instance("parses heredoc-wrapped patch", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const patchText = `cat <<'EOF'

*** Begin Patch

*** Add File: heredoc_test.txt

+heredoc content

*** End Patch

EOF`

yield* execute({ patchText }, ctx)

expect(yield* readText(path.join(test.directory, "heredoc_test.txt"))).toBe("heredoc content\n")

}),

)

it.instance("parses heredoc-wrapped patch without cat", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const patchText = `<<EOF

*** Begin Patch

*** Add File: heredoc_no_cat.txt

+no cat prefix

*** End Patch

EOF`

yield* execute({ patchText }, ctx)

expect(yield* readText(path.join(test.directory, "heredoc_no_cat.txt"))).toBe("no cat prefix\n")

}),

)

it.instance("matches with trailing whitespace differences", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "trailing_ws.txt")

// File has trailing spaces on some lines

yield* writeText(target, "line1 \nline2\nline3 \n")

// Patch doesn't have trailing spaces - should still match via rstrip pass

const patchText = "*** Begin Patch\n*** Update File: trailing_ws.txt\n@@\n-line2\n+changed\n*** End Patch"

yield* execute({ patchText }, ctx)

expect(yield* readText(target)).toBe("line1 \nchanged\nline3 \n")

}),

)

it.instance("matches with leading whitespace differences", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "leading_ws.txt")

// File has leading spaces

yield* writeText(target, " line1\nline2\n line3\n")

// Patch without leading spaces - should match via trim pass

const patchText = "*** Begin Patch\n*** Update File: leading_ws.txt\n@@\n-line2\n+changed\n*** End Patch"

yield* execute({ patchText }, ctx)

expect(yield* readText(target)).toBe(" line1\nchanged\n line3\n")

}),

)

it.instance("matches with Unicode punctuation differences", () =>

Effect.gen(function* () {

const test = yield* TestInstance

const { ctx } = makeCtx()

const target = path.join(test.directory, "unicode.txt")

// File has fancy Unicode quotes (U+201C, U+201D) and em-dash (U+2014)

const leftQuote = "\u201C"

const rightQuote = "\u201D"

const emDash = "\u2014"

yield* writeText(target, `He said ${leftQuote}hello${rightQuote}\nsome${emDash}dash\nend\n`)

// Patch uses ASCII equivalents - should match via normalized pass

// The replacement uses ASCII quotes from the patch (not preserving Unicode)

const patchText =

'*** Begin Patch\n*** Update File: unicode.txt\n@@\n-He said "hello"\n+He said "hi"\n*** End Patch'

yield* execute({ patchText }, ctx)

// Result has ASCII quotes because that's what the patch specifies

expect(yield* readText(target)).toBe(`He said "hi"\nsome${emDash}dash\nend\n`)

}),

)

})