chore: import upstream snapshot with attribution

.opencode/tools/format-code.ts

@@ -0,0 +1,123 @@
+/**
+ * ECC Custom Tool: Format Code
+ *
+ * Returns the formatter command that should be run for a given file.
+ * This avoids shell execution assumptions while still giving precise guidance.
+ * Supports cross-platform command generation.
+ */
+
+import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
+import * as path from "path"
+import * as fs from "fs"
+
+type Formatter = "biome" | "prettier" | "black" | "gofmt" | "rustfmt" | "swift-format"
+
+interface FormatResult {
+  success: boolean
+  formatter?: Formatter
+  command?: string
+  instructions?: string
+  message?: string
+  error?: string
+}
+
+const formatCodeTool: ToolDefinition = tool({
+  description:
+    "Detect formatter for a file and return the exact command to run (Biome, Prettier, Black, gofmt, rustfmt, swift-format). Supports cross-platform command generation.",
+  args: {
+    filePath: tool.schema.string().describe("Path to the file to format"),
+    formatter: tool.schema
+      .enum(["biome", "prettier", "black", "gofmt", "rustfmt", "swift-format"])
+      .optional()
+      .describe("Optional formatter override"),
+  },
+  async execute(args, context): Promise<string> {
+    try {
+      const cwd = context.worktree || context.directory
+      const ext = args.filePath.split(".").pop()?.toLowerCase() || ""
+      const detected = args.formatter || detectFormatter(cwd, ext)
+
+      if (!detected) {
+        return JSON.stringify({
+          success: false,
+          message: `No formatter detected for .${ext} files`,
+          supportedFormatters: ["biome", "prettier", "black", "gofmt", "rustfmt", "swift-format"],
+        })
+      }
+
+      const command = buildFormatterCommand(detected, args.filePath, cwd)
+      return JSON.stringify({
+        success: true,
+        formatter: detected,
+        command,
+        instructions: `Run this command:\n\n${command}`,
+        platform: process.platform,
+      })
+    } catch (error: unknown) {
+      const errorMessage = error instanceof Error ? error.message : String(error)
+      return JSON.stringify({
+        success: false,
+        error: `Failed to detect formatter: ${errorMessage}`,
+        filePath: args.filePath,
+      })
+    }
+  },
+})
+
+export default formatCodeTool
+
+function detectFormatter(cwd: string, ext: string): Formatter | null {
+  // Check for formatter config files
+  const hasConfig = (configFiles: string[]): boolean => {
+    return configFiles.some(configFile => fs.existsSync(path.join(cwd, configFile)))
+  }
+
+  // JavaScript/TypeScript files
+  if (["ts", "tsx", "js", "jsx", "json", "css", "scss", "md", "yaml", "yml"].includes(ext)) {
+    if (hasConfig(["biome.json", "biome.jsonc"])) {
+      return "biome"
+    }
+    return "prettier"
+  }
+
+  // Python files
+  if (["py", "pyi"].includes(ext)) {
+    return "black"
+  }
+
+  // Go files
+  if (ext === "go") {
+    return "gofmt"
+  }
+
+  // Rust files
+  if (ext === "rs") {
+    return "rustfmt"
+  }
+
+  // Swift files
+  if (ext === "swift") {
+    return "swift-format"
+  }
+
+  return null
+}
+
+function buildFormatterCommand(formatter: Formatter, filePath: string, cwd?: string): string {
+  // Normalize to forward slashes so the emitted command is identical on every
+  // platform. `path.normalize` yields backslashes on Windows, which broke the
+  // command string (and Windows CI); all formatter CLIs accept `/` on Windows.
+  const normalizedPath = path.normalize(filePath).split(path.sep).join("/")
+
+  // Build command based on formatter and platform
+  const commands: Record<Formatter, string> = {
+    biome: `npx @biomejs/biome format --write ${normalizedPath}`,
+    prettier: `npx prettier --write ${normalizedPath}`,
+    black: `black ${normalizedPath}`,
+    gofmt: `gofmt -w ${normalizedPath}`,
+    rustfmt: `rustfmt ${normalizedPath}`,
+    "swift-format": `swift-format format --in-place ${normalizedPath}`,
+  }
+
+  return commands[formatter]
+}