meilisearch/.github/scripts/is-latest-release.sh

#!/bin/sh

# Was used in our CIs to publish the latest docker image. Not used anymore, will be used again when v1 and v2 will be out and we will want to maintain multiple stable versions.
# Returns "true" or "false" (as a string) to be used in the `if` in GHA

# Checks if the current tag should be the latest (in terms of semver and not of release date).
# Ex: previous tag -> v2.1.1
#     new tag -> v1.20.3
#     The new tag (v1.20.3) should NOT be the latest
#     So it returns "false", the `latest tag` should not be updated for the release v1.20.3 and still need to correspond to v2.1.1

# GLOBAL
GREP_SEMVER_REGEXP='v\([0-9]*\)[.]\([0-9]*\)[.]\([0-9]*\)$' # i.e. v[number].[number].[number]

# FUNCTIONS

# semverParseInto and semverLT from https://github.com/cloudflare/semver_bash/blob/master/semver.sh

# usage: semverParseInto version major minor patch special
# version: the string version
# major, minor, patch, special: will be assigned by the function
semverParseInto() {
    local RE='[^0-9]*\([0-9]*\)[.]\([0-9]*\)[.]\([0-9]*\)\([0-9A-Za-z-]*\)'
    #MAJOR
    eval $2=`echo $1 | sed -e "s#$RE#\1#"`
    #MINOR
    eval $3=`echo $1 | sed -e "s#$RE#\2#"`
    #MINOR
    eval $4=`echo $1 | sed -e "s#$RE#\3#"`
    #SPECIAL
    eval $5=`echo $1 | sed -e "s#$RE#\4#"`
}

# usage: semverLT version1 version2
semverLT() {
    local MAJOR_A=0
    local MINOR_A=0
    local PATCH_A=0
    local SPECIAL_A=0

    local MAJOR_B=0
    local MINOR_B=0
    local PATCH_B=0
    local SPECIAL_B=0

    semverParseInto $1 MAJOR_A MINOR_A PATCH_A SPECIAL_A
    semverParseInto $2 MAJOR_B MINOR_B PATCH_B SPECIAL_B

    if [ $MAJOR_A -lt $MAJOR_B ]; then
        return 0
    fi
    if [ $MAJOR_A -le $MAJOR_B ] && [ $MINOR_A -lt $MINOR_B ]; then
        return 0
    fi
    if [ $MAJOR_A -le $MAJOR_B ] && [ $MINOR_A -le $MINOR_B ] && [ $PATCH_A -lt $PATCH_B ]; then
        return 0
    fi
    if [ "_$SPECIAL_A"  == "_" ] && [ "_$SPECIAL_B"  == "_" ] ; then
        return 1
    fi
    if [ "_$SPECIAL_A"  == "_" ] && [ "_$SPECIAL_B"  != "_" ] ; then
        return 1
    fi
    if [ "_$SPECIAL_A"  != "_" ] && [ "_$SPECIAL_B"  == "_" ] ; then
        return 0
    fi
    if [ "_$SPECIAL_A" < "_$SPECIAL_B" ]; then
        return 0
    fi

    return 1
}

# Returns the tag of the latest stable release (in terms of semver and not of release date)
get_latest() {
    temp_file='temp_file' # temp_file needed because the grep would start before the download is over
    curl -s 'https://api.github.com/repos/meilisearch/meilisearch/releases' > "$temp_file"
    releases=$(cat "$temp_file" | \
        grep -E "tag_name|draft|prerelease" \
        | tr -d ',"' | cut -d ':' -f2 | tr -d ' ')
        # Returns a list of [tag_name draft_boolean prerelease_boolean ...]
        # Ex: v0.10.1 false false v0.9.1-rc.1 false true v0.9.0 false false...

    i=0
    latest=""
    current_tag=""
    for release_info in $releases; do
        if [ $i -eq 0 ]; then # Cheking tag_name
            if echo "$release_info" | grep -q "$GREP_SEMVER_REGEXP"; then # If it's not an alpha or beta release
                current_tag=$release_info
            else
                current_tag=""
            fi
            i=1
        elif [ $i -eq 1 ]; then # Checking draft boolean
            if [ "$release_info" = "true" ]; then
                current_tag=""
            fi
            i=2
        elif [ $i -eq 2 ]; then # Checking prerelease boolean
            if [ "$release_info" = "true" ]; then
                current_tag=""
            fi
            i=0
            if [ "$current_tag" != "" ]; then # If the current_tag is valid
                if [ "$latest" = "" ]; then # If there is no latest yet
                    latest="$current_tag"
                else
                    semverLT $current_tag $latest # Comparing latest and the current tag
                    if [ $? -eq 1 ]; then
                        latest="$current_tag"
                    fi
                fi
            fi
        fi
    done

    rm -f "$temp_file"
    echo $latest
}

# MAIN
current_tag="$(echo $GITHUB_REF | tr -d 'refs/tags/')"
latest="$(get_latest)"

if [ "$current_tag" != "$latest" ]; then
    # The current release tag is not the latest
    echo "false"
else
    # The current release tag is the latest
    echo "true"
fi