fix: implement session ID extraction in start script and update tests to validate session resumption

Author: DevelopmentCats

registry/coder/modules/claude-code/main.test.ts

@@ -206,14 +206,16 @@ describe("claude-code", async () => {
       },
     });
 
+    // Create a mock session file so get_latest_session_id can extract the session ID
     const projectDir = "/home/coder/project";
     const projectDirName = projectDir.replace(/\//g, "-");
     const sessionDir = `/home/coder/.claude/projects/${projectDirName}`;
+    const testSessionId = "test-session-123";
     await execContainer(id, ["mkdir", "-p", sessionDir]);
     await execContainer(id, [
       "bash",
       "-c",
-      `echo '{"type":"user","isSidechain":false}' > ${sessionDir}/session-123.jsonl`,
+      `echo '{"type":"user","isSidechain":false,"sessionId":"${testSessionId}"}' > ${sessionDir}/session-123.jsonl`,
     ]);
 
     await execModuleScript(id);
@@ -223,7 +225,8 @@ describe("claude-code", async () => {
       "-c",
       "cat /home/coder/.claude-module/agentapi-start.log",
     ]);
-    expect(startLog.stdout).toContain("--continue");
+    expect(startLog.stdout).toContain("--resume");
+    expect(startLog.stdout).toContain(testSessionId);
   });
 
   test("pre-post-install-scripts", async () => {

registry/coder/modules/claude-code/scripts/start.sh

@@ -64,6 +64,41 @@ has_session_for_workdir() {
   return 1
 }
 
+get_latest_session_id() {
+  local workdir="$1"
+  local workdir_abs=$(realpath "$workdir" 2> /dev/null || echo "$workdir")
+  local project_dir_name=$(echo "$workdir_abs" | sed 's|/|-|g')
+  local project_sessions_dir="$HOME/.claude/projects/$project_dir_name"
+
+  if [ ! -d "$project_sessions_dir" ]; then
+    return 1
+  fi
+
+  local latest_session_id=""
+  local latest_time=0
+
+  for file in "$project_sessions_dir"/*.jsonl; do
+    [ -f "$file" ] || continue
+
+    if grep -q '"type":"user"' "$file" 2> /dev/null; then
+      if grep -q '"isSidechain":false' "$file" 2> /dev/null; then
+        local file_time=$(stat -c %Y "$file" 2> /dev/null || stat -f %m "$file" 2> /dev/null || echo 0)
+        if [ "$file_time" -gt "$latest_time" ]; then
+          latest_time=$file_time
+          latest_session_id=$(grep '"isSidechain":false' "$file" | grep '"sessionId"' | head -1 | grep -o '"sessionId":"[^"]*"' | cut -d'"' -f4)
+        fi
+      fi
+    fi
+  done
+
+  if [ -n "$latest_session_id" ]; then
+    echo "$latest_session_id"
+    return 0
+  else
+    return 1
+  fi
+}
+
 ARGS=()
 
 function start_agentapi() {
@@ -81,24 +116,39 @@ function start_agentapi() {
   if [ -n "$ARG_RESUME_SESSION_ID" ]; then
     echo "Using explicit resume_session_id: $ARG_RESUME_SESSION_ID"
     ARGS+=(--resume "$ARG_RESUME_SESSION_ID")
-    if [ -n "$ARG_DANGEROUSLY_SKIP_PERMISSIONS" ]; then
+    if [ "$ARG_DANGEROUSLY_SKIP_PERMISSIONS" = "true" ]; then
       ARGS+=(--dangerously-skip-permissions)
     fi
   elif [ "$ARG_CONTINUE" = "true" ]; then
     if has_session_for_workdir "$ARG_WORKDIR"; then
-      echo "Session detected for workdir: $ARG_WORKDIR"
-      ARGS+=(--continue)
-      if [ -n "$ARG_DANGEROUSLY_SKIP_PERMISSIONS" ]; then
-        ARGS+=(--dangerously-skip-permissions)
+      local session_id=$(get_latest_session_id "$ARG_WORKDIR")
+      if [ -n "$session_id" ]; then
+        echo "Session detected for workdir: $ARG_WORKDIR"
+        echo "Latest session ID: $session_id"
+        ARGS+=(--resume "$session_id")
+        if [ "$ARG_DANGEROUSLY_SKIP_PERMISSIONS" = "true" ]; then
+          ARGS+=(--dangerously-skip-permissions)
+        fi
+        echo "Resuming existing session with explicit session ID"
+      else
+        echo "Could not extract session ID, starting new session"
+        if [ -n "$ARG_AI_PROMPT" ]; then
+          ARGS+=(--dangerously-skip-permissions "$ARG_AI_PROMPT")
+          echo "Starting new session with prompt"
+        else
+          if [ "$ARG_DANGEROUSLY_SKIP_PERMISSIONS" = "true" ]; then
+            ARGS+=(--dangerously-skip-permissions)
+          fi
+          echo "Starting claude code session"
+        fi
       fi
-      echo "Resuming existing session"
     else
       echo "No existing session for workdir: $ARG_WORKDIR"
       if [ -n "$ARG_AI_PROMPT" ]; then
         ARGS+=(--dangerously-skip-permissions "$ARG_AI_PROMPT")
         echo "Starting new session with prompt"
       else
-        if [ -n "$ARG_DANGEROUSLY_SKIP_PERMISSIONS" ]; then
+        if [ "$ARG_DANGEROUSLY_SKIP_PERMISSIONS" = "true" ]; then
           ARGS+=(--dangerously-skip-permissions)
         fi
         echo "Starting claude code session"
@@ -110,7 +160,7 @@ function start_agentapi() {
       ARGS+=(--dangerously-skip-permissions "$ARG_AI_PROMPT")
       echo "Starting new session with prompt"
     else
-      if [ -n "$ARG_DANGEROUSLY_SKIP_PERMISSIONS" ]; then
+      if [ "$ARG_DANGEROUSLY_SKIP_PERMISSIONS" = "true" ]; then
         ARGS+=(--dangerously-skip-permissions)
       fi
       echo "Starting claude code session"