Add packcheck-remote to work with remote repositories directly

Author: adithyaov

README.md

@@ -197,6 +197,22 @@ well on the command line. For example,
 $ ./packcheck-safe.sh cabal-v2 PATH=/bin:/usr/bin:/opt/ghc/bin
 ```
 
+## packcheck-remote
+
+`packcheck-remote.sh` is a wrapper over `packcheck.sh`. It makes it easer to
+work with remote repositories.
+
+```
+$ ./packcheck-remote.sh --force \
+    --remote=https://github.com/user/repo \
+    --checkout=origin/master \
+    --merge=origin/branch \
+    --directory=./repo.packcheck \
+    -- cabal-v2 GHCVER=8.8.3
+```
+
+Use `./packcheck-remote.sh --help` for more information.
+
 ## Full Reference
 
 Please use `cabal` version 2.4 or later.

packcheck-remote.sh

@@ -0,0 +1,191 @@
+#!/usr/bin/env bash
+
+PACKCHECK_DIR="$(dirname $0)"
+PACKCHECK_EXE="$PACKCHECK_DIR/packcheck.sh"
+PWD="$(pwd)"
+DEFAULT_DIRECTORY_NAME="packcheck-remote-work"
+DEFAULT_DIRECTORY="$PWD/$DEFAULT_DIRECTORY_NAME"
+
+# $1: msg
+show_step() {
+  echo
+  echo "--------------------------------------------------"
+  echo "$1"
+  echo "--------------------------------------------------"
+}
+
+which_cmd() {
+  hash -r && type -P "$1" || true
+}
+
+# $1: executable (eg. git)
+require_cmd () {
+    if test -z "$(which_cmd $1)"
+    then
+        echo "Required command [$1] not found in PATH [$PATH]."
+        exit 1
+    else
+        echo "Using [$1] at [$(which_cmd $1)]"
+    fi
+}
+
+# $1: command
+function run_verbose() {
+    echo "$*"
+    bash -c "$*"
+}
+
+# $1: Remote repository
+# $2: Revision to checkout
+# $3: Revision to merge into $2
+# $4: Directory to clone into
+# $5: Force mode
+# $6: Packcheck cli options
+try_git_clone_and_merge() {
+
+    # Check for prerequisites
+    require_cmd git
+
+    local remote="$1"
+    local rev="$2"
+    local merge="$3"
+    local dir="$4"
+    local force_mode="$5"
+    local packcheck_cli_opts="$6"
+
+    if test -z "$dir"
+    then
+        dir="$DEFAULT_DIRECTORY"
+        echo "No directory specified to clone to."
+        echo "Using $dir"
+    fi
+
+    if test -z "$remote"
+    then
+        echo "No remote repository provided."
+        echo "Skipping cloning."
+        return
+    fi
+
+    if test -z "$rev"
+    then
+        echo "No revision given."
+        echo "Defaulting to 'origin/master'."
+        rev="origin/master"
+    fi
+
+    if test -d "$dir"
+    then
+        echo "$dir already exists"
+
+        if [ "$force_mode" == "true" ];
+        then
+            echo "Forcing the deletion of the directory."
+            echo "Removing $dir"
+            rm -rf "$dir" || exit 1
+        else
+            echo "Set the script to force mode to force the deletion."
+            return
+        fi
+    fi
+
+    mkdir -p "$dir" || exit 1
+
+    run_verbose "git clone $remote $dir" || exit 1
+
+    cd "$dir" || exit 1
+    run_verbose "git branch $rev" || exit 1
+
+    if test -n "$merge"
+    then
+        # This will fail is there are any merge conflicts
+        run_verbose "git merge -X theirs $merge --no-edit --commit" || exit 1
+    fi
+
+    show_step "Running packcheck"
+    # Run packcheck here
+    run_verbose "$PACKCHECK_EXE $packcheck_cli_opts"
+
+    # Go back to where the script was executed from
+    cd "$PWD" || exit 1
+}
+
+# Arguments for the command line
+FORCE="false"
+REMOTE=""
+CHECKOUT=""
+MERGE=""
+DIRECTORY=""
+PACKCHECK_CLI_OPTS=""
+
+function run_help() {
+    local script=$(basename $0)
+
+    echo
+    echo "USAGE: --option[=value]"
+    echo
+    echo "-f (or) --force: Puts the script in force mode. This is ideal for CIs."
+    echo "-h (or) --help:  Print help."
+    echo "--remote:        Repository to clone."
+    echo "--checkout:      Revision to checkout. Defaults to 'origin/master'."
+    echo "--merge:         Revision to merge in the checked out branch."
+    echo "--directory:     Directory to clone the repository into."
+    echo "                 Defaults to '$DEFAULT_DIRECTORY_NAME' under the present working directory."
+    echo
+    echo "All the arguments after '--' are passed to packcheck"
+    echo
+
+    echo
+    echo "EXAMPLE:"
+    echo
+    echo "$script --force \\"
+    echo "        --remote=https://github.com/user/repo \\"
+    echo "        --checkout=origin/master \\"
+    echo "        --merge=origin/branch \\"
+    echo "        --directory=./repo.packcheck \\"
+    echo "        -- cabal-v2 GHCVER=8.8.3"
+    echo
+}
+
+# Program entry point
+for i in "$@"
+do
+    case $i in
+        -f|--force)
+            FORCE="true"
+            shift
+            ;;
+        -h|--help)
+            run_help
+            exit 0
+            ;;
+        --remote=*)
+            REMOTE="${i#*=}"
+            shift
+            ;;
+        --checkout=*)
+            CHECKOUT="${i#*=}"
+            shift
+            ;;
+        --merge=*)
+            MERGE="${i#*=}"
+            shift
+            ;;
+        --directory=*)
+            DIRECTORY="${i#*=}"
+            shift
+            ;;
+        --)
+            shift
+            PACKCHECK_CLI_OPTS=$@
+            break
+            ;;
+        *)
+            echo "Unknown argument to packcheck-remote"
+            run_help
+            exit 1
+            ;;
+    esac
+done
+
+try_git_clone_and_merge "$REMOTE" "$CHECKOUT" "$MERGE" "$DIRECTORY" "$FORCE" "$PACKCHECK_CLI_OPTS"