Improve error handling

cmd/command.go

@@ -35,6 +35,12 @@ Constraints:
 		}
 
 		index, err := strconv.Atoi(args[1])
+		if err != nil {
+			return err
+		}
+		if index >= len(op.Commands) {
+			return fmt.Errorf("command index is too large")
+		}
 		fmt.Print(op.Commands[index])
 		return nil
 	},

cmd/upload.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"encoding/json"
 	"fmt"
 	"strconv"
 
@@ -42,8 +43,17 @@ Constraints:
 		if err != nil {
 			return err
 		}
-		fmt.Println(url)
-		fmt.Println(offset)
+		j, err := json.Marshal(struct {
+			URL    string `json:"url"`
+			Offset int64  `json:"offset"`
+		}{
+			URL:    url,
+			Offset: offset,
+		})
+		if err != nil {
+			return err
+		}
+		fmt.Println(string(j))
 		return nil
 	},
 }

mop.bash

@@ -1,14 +1,17 @@
 #!/bin/bash
 
-MOP_CONFIG="config.json"
+MOP_CONFIG="$HOME/.mop.json"
+GH_MOP="gh mop --config=${MOP_CONFIG}"
+
+# For development
+MOP_CONFIG=".mop.json"
 GH_MOP="go run main.go --config=${MOP_CONFIG}"
-# GH_MOP="gh mop --config=${MOP_CONFIG}"
 
 # Start an operation.
 # $1: The issue number for the operation.
 function mop-start() {
   if [ -z $1 ]; then
-    echo "Error: The issue number is required."
+    echo "Error: The issue number is required. Usage: \"mop-start <issue number>\"."
     return 1
   fi
 
@@ -22,59 +25,84 @@ function mop-start() {
     return 1
   fi
 
+  if ! command -v gh &> /dev/null
+  then
+      echo "gh could not be found. Please install it with `sudo apt install gh`"
+      return 1
+  fi
+  if ! gh auth status &> /dev/null
+  then
+      echo "You are not logged in to github. Please run `gh auth login`"
+      return 1
+  fi
+  if ! command -v jq &> /dev/null
+  then
+      echo "jq could not be found. Please install it with `sudo apt install jq`"
+      return 1
+  fi
+  if ! command -v script &> /dev/null
+  then
+      echo "script could not be found. Please install it with `sudo apt install script`"
+      return 1
+  fi
+
   export MOP_REPO=$(cat $MOP_CONFIG | jq -r .repository)
   if [ -z "$MOP_REPO" ]; then
     echo "Error: The repository name is not set in the config file."
-    clear-mop
+    mop-clear-env
     return 1
   fi
   export MOP_DATADIR=$(cat $MOP_CONFIG | jq -r .datadir)
   if [ -z "$MOP_DATADIR" ]; then
     echo "Error: The data directory is not set in the config file."
-    clear-mop
+    mop-clear-env
     return 1
   fi
   export MOP_ISSUE=$1
   export MOP_STEP=0
+  export MOP_OFFSET=0
 
   mkdir -p ${MOP_DATADIR}/${MOP_REPO}/${MOP_ISSUE} || return $?
 
   $GH_MOP operation $MOP_ISSUE
   status=$?
   if [ $status -ne 0 ]; then
-    clear-mop
+    mop-clear-env
     return $status
   fi
   export MOP_COMMAND_COUNT=$(cat ${MOP_DATADIR}/${MOP_REPO}/${MOP_ISSUE}/operation.json | jq '.commands | length')
 
-  script -q -f -a ${MOP_DATADIR}/${MOP_REPO}/${MOP_ISSUE}/typescript.txt
+  local record=${MOP_DATADIR}/${MOP_REPO}/${MOP_ISSUE}/typescript
+  if [ -f $record ]; then
+    mv $record ${record}_$(date +%Y%m%d%H%M%S)
+  fi
+  script -q -f -a $record
   status=$?
   if [ $status -ne 0 ]; then
-    clear-mop
+    mop-clear-env
     return $status
   fi
+  mop-clear-env
+  return 0
 }
 
-# Clear environment variables and functions for mop.
-function clear-mop() {
+# Clear environment variables
+function mop-clear-env() {
   unset MOP_REPO
   unset MOP_DATADIR
   unset MOP_ISSUE
   unset MOP_STEP
+  unset MOP_OFFSET
   unset MOP_COMMAND_COUNT
-
-  unset -f next
-  unset -f prev
-  unset -f insert
-  unset -f upload
-  unset -f list
-  unset -f utilities
-  unset -f help
 }
 
-
 if [ -n "$MOP_ISSUE" ]; then
   export PS1="[\${MOP_REPO}#\${MOP_ISSUE}:Step\${MOP_STEP}]$ "
+  trap 'finish' EXIT
+
+  echo "The operation is started. Issue: $MOP_ISSUE."
+  echo "If you want to read the help, type \"help\"."
+
   # Move to the next step in the operation.
   function next() {
     if [ $MOP_STEP -eq $(($MOP_COMMAND_COUNT - 1)) ]; then
@@ -103,7 +131,15 @@ if [ -n "$MOP_ISSUE" ]; then
   # Upload the results of executed commands.
   # The result is uploaded to the issue's comment.
   function upload() {
-    $GH_MOP upload $MOP_ISSUE ${MOP_DATADIR}/${MOP_REPO}/${MOP_ISSUE}/typescript.txt
+    local result
+    result=$($GH_MOP upload --offset $MOP_OFFSET $MOP_ISSUE ${MOP_DATADIR}/${MOP_REPO}/${MOP_ISSUE}/typescript)
+    status=$?
+    if [ $status -ne 0 ]; then
+      return $status
+    fi
+    MOP_OFFSET=$(echo $result | jq -r .offset)
+    url=$(echo $result | jq -r .url)
+    echo "The result is uploaded to $url"
   }
 
   # List the commands in the current operation.
@@ -132,6 +168,25 @@ if [ -n "$MOP_ISSUE" ]; then
     echo "  MOP_REPO: The repository name."
     echo "  MOP_ISSUE: The issue number for the operation."
     echo "  MOP_STEP: The step number in the operation."
+    echo "  MOP_OFFSET: The offset of the result in the issue comment."
+    echo "  MOP_COMMAND_COUNT: The number of commands in the operation."
+  }
+
+  function finish() {
+    mop-clear-env
+
+    unset -f next
+    unset -f prev
+    unset -f insert
+    unset -f upload
+    unset -f list
+    unset -f utilities
+    unset -f help
+    unset -f finish
+
+    bind -r "\C-t"
+    bind -r "\C-j"
+    bind -r "\C-o"
   }
 
   bind -x '"\C-t":"insert"'

pkg/command/upload.go

@@ -27,6 +27,9 @@ func UploadResult(client *github.Client, issue int, filepath string, offset int6
 		return "", 0, fmt.Errorf("offset is too large")
 	}
 	content = content[offset:]
+	if len(content) == 0 {
+		return "", 0, fmt.Errorf("no content to upload")
+	}
 
 	comment := formatAsCodeBlock(content)
 	url, err := client.PostComment(issue, comment)