gomodgraph.sh

#!/usr/bin/bash

function wrapInGraph() {
    # print beginning of DOT file, including formatting commands
    cat <<END
digraph G {
    rankdir=LR;
    graph [
        K=1.0,
        overlap=false,
        splines = spline,
    ];
    node [
        shape=box
        style="rounded"
        # color="#9999ff",
        # fontcolor="#9999ff",
        color="#666666",
        fontcolor="#666666",
        # fontname="Helvetica",
    ];
    edge [
        # arrowsize=2,
        # color="#9999ff",
    ];
END

    # Read `go mod graph` output from stdin as
    #     parent-module child-module
    # Format it as DOT node pairs
    #     "parent-module" -> "child-module" [color="#cc33cc"]
    # Set color for edges by cycling through color list @cl
    # Write it to stdout
    perl -e '$c=0; @cl=("cc3333","33cc33","3333cc","cccc33","cc33cc","33cccc"); $cls=scalar @cl;
        while(<>){ $col="$cl[$c%$cls]"; s/^(\S+) (\S+)$/    "$1" -> "$2" [color="#$col"]/;
        print;
        $c++;}'

    # Close the digraph definition
    echo '}'
}


# Create a graph of the module dependencies, treating different versions as distinct
go mod graph |
    wrapInGraph |
    dot -Tpng > modgraph.png

# Create a graph of the module dependencies, treating different versions as the same module
go mod graph |
    perl -pe 's/^(\S+?)(?:\@\S+)? (\S+?)(?:\@\S+)?$/$1 $2/' |  # strip off the version info
    sort | uniq |  # remove duplicates
    wrapInGraph |
    dot -Tpng > modgraph-unversioned.png