git init | first commit

opencode-config/plugin/fail-fast.ts

@@ -0,0 +1,156 @@
+/**
+ * Fail Fast Plugin
+ * Converts denied permissions and missing shell utilities into explicit task
+ * failures so agents do not repeatedly retry or stall on unavailable actions.
+ */
+
+import type { Plugin } from "@opencode-ai/plugin"
+
+const MISSING_UTILITY_PATTERNS = [
+  /(?:^|\n)(?:sh|bash|zsh|fish):\s*(?<command>[\w./-]+):\s*command not found\b/i,
+  /(?:^|\n)(?<command>[\w./-]+):\s*command not found\b/i,
+  /(?:^|\n)(?:sh|bash|zsh|fish):\s*(?<command>[\w./-]+):\s*not found\b/i,
+  /(?:^|\n)(?<command>[\w./-]+):\s*not found\b/i,
+  /(?:^|\n)env:\s*(?<command>[\w./-]+):\s*No such file or directory\b/i,
+  /(?:^|\n).*spawn\s+(?<command>[\w./-]+)\s+ENOENT\b/i,
+]
+
+const SHELL_BUILTINS = new Set([
+  "alias",
+  "break",
+  "cd",
+  "command",
+  "continue",
+  "dirs",
+  "echo",
+  "eval",
+  "exec",
+  "exit",
+  "export",
+  "false",
+  "fg",
+  "hash",
+  "jobs",
+  "popd",
+  "printf",
+  "pushd",
+  "pwd",
+  "read",
+  "return",
+  "set",
+  "shift",
+  "source",
+  "test",
+  "true",
+  "type",
+  "ulimit",
+  "unalias",
+  "unset",
+])
+
+function normalizeCommand(command: string): string {
+  return command.replace(/^['"]|['"]$/g, "").trim()
+}
+
+function findMissingUtility(output: string): string | undefined {
+  for (const pattern of MISSING_UTILITY_PATTERNS) {
+    const match = pattern.exec(output)
+    const command = match?.groups?.command
+
+    if (!command) {
+      continue
+    }
+
+    const normalized = normalizeCommand(command)
+
+    if (normalized && !SHELL_BUILTINS.has(normalized)) {
+      return normalized
+    }
+  }
+
+  return undefined
+}
+
+function getBashCommand(args: unknown): string | undefined {
+  if (!args || typeof args !== "object") {
+    return undefined
+  }
+
+  const record = args as Record<string, unknown>
+  const command = record.command ?? record.cmd ?? record.script
+
+  return typeof command === "string" ? command : undefined
+}
+
+function describePermission(input: {
+  type: string
+  pattern?: string | string[]
+  title: string
+}): string {
+  const pattern = Array.isArray(input.pattern)
+    ? input.pattern.join(", ")
+    : input.pattern
+
+  return [input.type, pattern].filter(Boolean).join(" ") || input.title
+}
+
+export const FailFastPlugin = (async () => {
+  return {
+    "permission.ask": async (input, output) => {
+      if (output.status !== "deny") {
+        return
+      }
+
+      throw new Error(
+        [
+          "FAIL_FAST_PERMISSION_DENIED: A required tool permission was denied.",
+          `Permission: ${describePermission(input)}`,
+          `Title: ${input.title}`,
+          "Next action: reroute to an agent with the required permission, request permission from the user, or fail the task explicitly.",
+        ].join("\n")
+      )
+    },
+
+    "tool.execute.before": async (input, output) => {
+      if (input.tool !== "bash") {
+        return
+      }
+
+      const command = getBashCommand(output.args)
+
+      if (command === undefined || command.trim()) {
+        return
+      }
+
+      throw new Error(
+        "FAIL_FAST_INVALID_COMMAND: The bash tool was called without a command. Stop and report the missing command instead of retrying."
+      )
+    },
+
+    "tool.execute.after": async (input, output) => {
+      if (input.tool !== "bash") {
+        return
+      }
+
+      const missingUtility = findMissingUtility(output.output ?? "")
+
+      if (!missingUtility) {
+        return
+      }
+
+      const command = getBashCommand(input.args)
+
+      const commandLine = command ? `\nCommand: ${command}` : ""
+
+      throw new Error(
+        [
+          `FAIL_FAST_MISSING_UTILITY: Required shell utility "${missingUtility}" is not available in this environment.`,
+          commandLine.trim(),
+          "Next action: install or mount the missing utility, choose a different validation path, or fail the task explicitly.",
+        ]
+          .filter(Boolean)
+          .join("\n")
+      )
+    },
+  }
+}) satisfies Plugin