A few more fixes

Author: DilumAluthge

src/Operations.jl

@@ -1819,19 +1819,28 @@ function set_force_latest_compatible_version!(ctx::Types.Context,
     has_compat = haskey(ctx.env.project.compat, dep_name)
     if has_compat
         old_compat_entry_string = ctx.env.project.compat[dep_name]
+        old_compat_entry_spec = Types.semver_spec(old_compat_entry_string)
+        all_registered_versions = get_all_registered_versions(ctx, dep_uuid)
         latest_compatible_version = get_latest_compatible_version(
             ctx,
             dep_uuid,
-            old_compat_entry_string,
+            old_compat_entry_spec,
+            all_registered_versions,
         )
         earliest_backwards_compatible_version = get_earliest_backwards_compatible_version(latest_compatible_version)
+        all_compatible_earliest_to_latest = get_all_compatible_earliest_to_latest(
+            old_compat_entry_spec,
+            earliest_backwards_compatible_version,
+            latest_compatible_version,
+            all_registered_versions,
+        )
         if allow_earlier_backwards_compatible_versions
-            version_to_use_for_compat = earliest_backwards_compatible_version
+            new_compat_entry_string = join(string.(Ref("="), all_compatible_earliest_to_latest), ", ")
         else
-            version_to_use_for_compat = latest_compatible_version
+            new_compat_entry_string = "=$(latest_compatible_version)"
         end
-        new_compat_entry_string = "^$(version_to_use_for_compat)"
         ctx.env.project.compat[dep_name] = new_compat_entry_string
+        @info("Setting new `[compat]` entry: `$(dep_name) = \"$(new_compat_entry_string)\"`")
     else
         if dep_name != target_name
             @warn(
@@ -1843,17 +1852,31 @@ function set_force_latest_compatible_version!(ctx::Types.Context,
     return nothing
 end
 
-function get_earliest_backwards_compatible_version(ver::Base.VersionNumber)
-    (ver.major > 0) && return Base.VersionNumber(ver.major, 0, 0)
-    (ver.minor > 0) && return Base.VersionNumber(0, ver.minor, 0)
-    return Base.VersionNumber(0, 0, ver.patch)
+function get_all_compatible_earliest_to_latest(compat_spec::VersionSpec,
+                                               earliest_ver::VersionNumber,
+                                               latest_ver::VersionNumber,
+                                               all_registered_versions::Set{VersionNumber})
+    compatible_versions = Set{VersionNumber}()
+    for ver in all_registered_versions
+        if earliest_ver <= ver <= latest_ver
+            if ver in compat_spec
+                push!(compatible_versions, ver)
+            end
+        end
+    end
+    return sort(collect(compatible_versions))
+end
+
+function get_earliest_backwards_compatible_version(ver::VersionNumber)
+    (ver.major > 0) && return VersionNumber(ver.major, 0, 0)
+    (ver.minor > 0) && return VersionNumber(0, ver.minor, 0)
+    return VersionNumber(0, 0, ver.patch)
 end
 
 function get_latest_compatible_version(ctx::Types.Context,
                                        uuid::Base.UUID,
-                                       compat_entry_string::AbstractString)
-    all_registered_versions = get_all_registered_versions(ctx, uuid)
-    compat_spec = Pkg.Types.semver_spec(compat_entry_string)
+                                       compat_spec::VersionSpec,
+                                       all_registered_versions::Set{VersionNumber})
     compatible_versions = filter(in(compat_spec), all_registered_versions)
     latest_compatible_version = maximum(compatible_versions)
     return latest_compatible_version