Merge pull request #7726 from hercules-ci/flake-show-when-empty-hide

nix flake show: Ignore empty attrsets
This commit is contained in:
Eelco Dolstra 2023-02-01 15:49:13 +01:00 committed by GitHub
commit 845b7f067d
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2 changed files with 88 additions and 1 deletions

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@ -1002,6 +1002,61 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
auto flake = std::make_shared<LockedFlake>(lockFlake()); auto flake = std::make_shared<LockedFlake>(lockFlake());
auto localSystem = std::string(settings.thisSystem.get()); auto localSystem = std::string(settings.thisSystem.get());
std::function<bool(
eval_cache::AttrCursor & visitor,
const std::vector<Symbol> &attrPath,
const Symbol &attr)> hasContent;
// For frameworks it's important that structures are as lazy as possible
// to prevent infinite recursions, performance issues and errors that
// aren't related to the thing to evaluate. As a consequence, they have
// to emit more attributes than strictly (sic) necessary.
// However, these attributes with empty values are not useful to the user
// so we omit them.
hasContent = [&](
eval_cache::AttrCursor & visitor,
const std::vector<Symbol> &attrPath,
const Symbol &attr) -> bool
{
auto attrPath2(attrPath);
attrPath2.push_back(attr);
auto attrPathS = state->symbols.resolve(attrPath2);
const auto & attrName = state->symbols[attr];
auto visitor2 = visitor.getAttr(attrName);
if ((attrPathS[0] == "apps"
|| attrPathS[0] == "checks"
|| attrPathS[0] == "devShells"
|| attrPathS[0] == "legacyPackages"
|| attrPathS[0] == "packages")
&& (attrPathS.size() == 1 || attrPathS.size() == 2)) {
for (const auto &subAttr : visitor2->getAttrs()) {
if (hasContent(*visitor2, attrPath2, subAttr)) {
return true;
}
}
return false;
}
if ((attrPathS.size() == 1)
&& (attrPathS[0] == "formatter"
|| attrPathS[0] == "nixosConfigurations"
|| attrPathS[0] == "nixosModules"
|| attrPathS[0] == "overlays"
)) {
for (const auto &subAttr : visitor2->getAttrs()) {
if (hasContent(*visitor2, attrPath2, subAttr)) {
return true;
}
}
return false;
}
// If we don't recognize it, it's probably content
return true;
};
std::function<nlohmann::json( std::function<nlohmann::json(
eval_cache::AttrCursor & visitor, eval_cache::AttrCursor & visitor,
const std::vector<Symbol> & attrPath, const std::vector<Symbol> & attrPath,
@ -1027,7 +1082,12 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
{ {
if (!json) if (!json)
logger->cout("%s", headerPrefix); logger->cout("%s", headerPrefix);
auto attrs = visitor.getAttrs(); std::vector<Symbol> attrs;
for (const auto &attr : visitor.getAttrs()) {
if (hasContent(visitor, attrPath, attr))
attrs.push_back(attr);
}
for (const auto & [i, attr] : enumerate(attrs)) { for (const auto & [i, attr] : enumerate(attrs)) {
const auto & attrName = state->symbols[attr]; const auto & attrName = state->symbols[attr];
bool last = i + 1 == attrs.size(); bool last = i + 1 == attrs.size();

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@ -37,3 +37,30 @@ in
assert show_output.legacyPackages.${builtins.currentSystem}.hello.name == "simple"; assert show_output.legacyPackages.${builtins.currentSystem}.hello.name == "simple";
true true
' '
# Test that attributes are only reported when they have actual content
cat >flake.nix <<EOF
{
description = "Bla bla";
outputs = inputs: rec {
apps.$system = { };
checks.$system = { };
devShells.$system = { };
legacyPackages.$system = { };
packages.$system = { };
packages.someOtherSystem = { };
formatter = { };
nixosConfigurations = { };
nixosModules = { };
};
}
EOF
nix flake show --json --all-systems > show-output.json
nix eval --impure --expr '
let show_output = builtins.fromJSON (builtins.readFile ./show-output.json);
in
assert show_output == { };
true
'