Add all eligible reviewers to Gitlab MR

setReviewers.sh

#!/usr/bin/env bash
set -e

# Ensure required tools are installed
if ! command -v glab &> /dev/null; then
    echo "Error: glab CLI is not installed. Please install it before running this script."
    exit 1
fi

if ! command -v jq &> /dev/null; then
    echo "Error: jq is not installed. Please install it before running this script."
    exit 1
fi

# Get the MR details in JSON format
MR_JSON=$(glab mr view -F json)

# Extract the numeric MR ID
MR_ID_NUM=$(echo "$MR_JSON" | jq '.id')

if [ -z "$MR_ID_NUM" ] || [ "$MR_ID_NUM" = "null" ]; then
  echo "Could not extract MR ID from glab mr view output."
  exit 1
fi

# Construct the global MR ID for GraphQL API
MR_ID="gid://gitlab/MergeRequest/$MR_ID_NUM"

# Extract project path and MR IID
PROJECT_PATH=$(echo "$MR_JSON" | jq -r '.references.full' | sed 's/!.*$//')
MR_IID=$(echo "$MR_JSON" | jq -r '.iid')

if [ -z "$PROJECT_PATH" ] || [ -z "$MR_IID" ]; then
  echo "Could not extract project path or MR IID."
  exit 1
fi

# GraphQL query to get eligible approvers and current reviewers
QUERY=$(cat <<EOF
query {
  mergeRequest(id: "$MR_ID") {
    approvalState {
      rules {
        approvalsRequired
        eligibleApprovers {
          name
          username
        }
      }
    }
    reviewers {
      nodes {
        username
      }
    }
  }
}
EOF
)

# Get the list of eligible approvers
RESPONSE=$(glab api graphql -f query="$QUERY")
if echo "$RESPONSE" | jq -e '.errors' >/dev/null; then
  echo "Error fetching merge request data:"
  echo "$RESPONSE" | jq -r '.errors[] | .message'
  exit 1
fi

REVIEWERS=$(echo "$RESPONSE" | jq -r '.data.mergeRequest.approvalState.rules[].eligibleApprovers[]?.username' | sort -u)

if [ -z "$REVIEWERS" ]; then
  echo "No eligible reviewers found."
  exit 1
fi

# Convert reviewers to GraphQL array format
REVIEWERS_ARRAY=$(printf '"%s",' $REVIEWERS)
REVIEWERS_ARRAY="[${REVIEWERS_ARRAY%,}]"

# Mutation to set reviewers with operationMode: APPEND
MUTATION=$(cat <<EOF
mutation {
  mergeRequestSetReviewers(
    input: {
      projectPath: "$PROJECT_PATH",
      iid: "$MR_IID",
      reviewerUsernames: $REVIEWERS_ARRAY,
      operationMode: APPEND
    }
  ) {
    errors
    mergeRequest {
      id
      title
      approvalsRequired
      reviewers {
        nodes {
          name
          username
        }
      }
    }
  }
}
EOF
)

# Run the mutation
MUTATION_RESPONSE=$(glab api graphql -f query="$MUTATION")
if echo "$MUTATION_RESPONSE" | jq -e '.errors' >/dev/null; then
  echo "Error setting reviewers:"
  echo "$MUTATION_RESPONSE" | jq -r '.errors[] | .message'
  exit 1
fi

# Check for errors in the mutation response
ERROR_COUNT=$(echo "$MUTATION_RESPONSE" | jq '.data.mergeRequestSetReviewers.errors | length')
if [ "$ERROR_COUNT" -gt 0 ]; then
  echo "Errors encountered:"
  echo "$MUTATION_RESPONSE" | jq -r '.data.mergeRequestSetReviewers.errors[]'
  exit 1
else
  echo "Reviewers updated successfully."
  echo "Current reviewers:"
  echo "$MUTATION_RESPONSE" | jq -r '.data.mergeRequestSetReviewers.mergeRequest.reviewers.nodes[] | "Reviewer: \(.name) (\(.username))"'
fi