lix/tests/unit/libexpr/value/print.cc
Rebecca Turner 0fa08b4516
Unify and refactor value printing
Previously, there were two mostly-identical value printers -- one in
`libexpr/eval.cc` (which didn't force values) and one in
`libcmd/repl.cc` (which did force values and also printed ANSI color
codes).

This PR unifies both of these printers into `print.cc` and provides a
`PrintOptions` struct for controlling the output, which allows for
toggling whether values are forced, whether repeated values are tracked,
and whether ANSI color codes are displayed.

Additionally, `PrintOptions` allows tuning the maximum number of
attributes, list items, and bytes in a string that will be displayed;
this makes it ideal for contexts where printing too much output (e.g.
all of Nixpkgs) is distracting. (As requested by @roberth in
https://github.com/NixOS/nix/pull/9554#issuecomment-1845095735)

Please read the tests for example output.

Future work:
- It would be nice to provide this function as a builtin, perhaps
  `builtins.toStringDebug` -- a printing function that never fails would
  be useful when debugging Nix code.
- It would be nice to support customizing `PrintOptions` members on the
  command line, e.g. `--option to-string-max-attrs 1000`.
2024-01-11 16:34:36 -08:00

817 lines
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C++

#include "tests/libexpr.hh"
#include "value.hh"
#include "print.hh"
namespace nix {
using namespace testing;
struct ValuePrintingTests : LibExprTest
{
template<class... A>
void test(Value v, std::string_view expected, A... args)
{
std::stringstream out;
v.print(state, out, args...);
ASSERT_EQ(out.str(), expected);
}
};
TEST_F(ValuePrintingTests, tInt)
{
Value vInt;
vInt.mkInt(10);
test(vInt, "10");
}
TEST_F(ValuePrintingTests, tBool)
{
Value vBool;
vBool.mkBool(true);
test(vBool, "true");
}
TEST_F(ValuePrintingTests, tString)
{
Value vString;
vString.mkString("some-string");
test(vString, "\"some-string\"");
}
TEST_F(ValuePrintingTests, tPath)
{
Value vPath;
vPath.mkString("/foo");
test(vPath, "\"/foo\"");
}
TEST_F(ValuePrintingTests, tNull)
{
Value vNull;
vNull.mkNull();
test(vNull, "null");
}
TEST_F(ValuePrintingTests, tAttrs)
{
Value vOne;
vOne.mkInt(1);
Value vTwo;
vTwo.mkInt(2);
BindingsBuilder builder(state, state.allocBindings(10));
builder.insert(state.symbols.create("one"), &vOne);
builder.insert(state.symbols.create("two"), &vTwo);
Value vAttrs;
vAttrs.mkAttrs(builder.finish());
test(vAttrs, "{ one = 1; two = 2; }");
}
TEST_F(ValuePrintingTests, tList)
{
Value vOne;
vOne.mkInt(1);
Value vTwo;
vTwo.mkInt(2);
Value vList;
state.mkList(vList, 5);
vList.bigList.elems[0] = &vOne;
vList.bigList.elems[1] = &vTwo;
vList.bigList.size = 3;
test(vList, "[ 1 2 «nullptr» ]");
}
TEST_F(ValuePrintingTests, vThunk)
{
Value vThunk;
vThunk.mkThunk(nullptr, nullptr);
test(vThunk, "«thunk»");
}
TEST_F(ValuePrintingTests, vApp)
{
Value vApp;
vApp.mkApp(nullptr, nullptr);
test(vApp, "«thunk»");
}
TEST_F(ValuePrintingTests, vLambda)
{
Env env {
.up = nullptr,
.values = { }
};
PosTable::Origin origin((std::monostate()));
auto posIdx = state.positions.add(origin, 1, 1);
auto body = ExprInt(0);
auto formals = Formals {};
ExprLambda eLambda(posIdx, createSymbol("a"), &formals, &body);
Value vLambda;
vLambda.mkLambda(&env, &eLambda);
test(vLambda, "«lambda @ «none»:1:1»");
eLambda.setName(createSymbol("puppy"));
test(vLambda, "«lambda puppy @ «none»:1:1»");
}
TEST_F(ValuePrintingTests, vPrimOp)
{
Value vPrimOp;
PrimOp primOp{
.name = "puppy"
};
vPrimOp.mkPrimOp(&primOp);
test(vPrimOp, "«primop puppy»");
}
TEST_F(ValuePrintingTests, vPrimOpApp)
{
PrimOp primOp{
.name = "puppy"
};
Value vPrimOp;
vPrimOp.mkPrimOp(&primOp);
Value vPrimOpApp;
vPrimOpApp.mkPrimOpApp(&vPrimOp, nullptr);
test(vPrimOpApp, "«partially applied primop puppy»");
}
TEST_F(ValuePrintingTests, vExternal)
{
struct MyExternal : ExternalValueBase
{
public:
std::string showType() const override
{
return "";
}
std::string typeOf() const override
{
return "";
}
virtual std::ostream & print(std::ostream & str) const override
{
str << "testing-external!";
return str;
}
} myExternal;
Value vExternal;
vExternal.mkExternal(&myExternal);
test(vExternal, "testing-external!");
}
TEST_F(ValuePrintingTests, vFloat)
{
Value vFloat;
vFloat.mkFloat(2.0);
test(vFloat, "2");
}
TEST_F(ValuePrintingTests, vBlackhole)
{
Value vBlackhole;
vBlackhole.mkBlackhole();
test(vBlackhole, "«potential infinite recursion»");
}
TEST_F(ValuePrintingTests, depthAttrs)
{
Value vOne;
vOne.mkInt(1);
Value vTwo;
vTwo.mkInt(2);
BindingsBuilder builderEmpty(state, state.allocBindings(0));
Value vAttrsEmpty;
vAttrsEmpty.mkAttrs(builderEmpty.finish());
BindingsBuilder builder(state, state.allocBindings(10));
builder.insert(state.symbols.create("one"), &vOne);
builder.insert(state.symbols.create("two"), &vTwo);
builder.insert(state.symbols.create("nested"), &vAttrsEmpty);
Value vAttrs;
vAttrs.mkAttrs(builder.finish());
BindingsBuilder builder2(state, state.allocBindings(10));
builder2.insert(state.symbols.create("one"), &vOne);
builder2.insert(state.symbols.create("two"), &vTwo);
builder2.insert(state.symbols.create("nested"), &vAttrs);
Value vNested;
vNested.mkAttrs(builder2.finish());
test(vNested, "{ nested = { ... }; one = 1; two = 2; }", PrintOptions { .maxDepth = 1 });
test(vNested, "{ nested = { nested = { ... }; one = 1; two = 2; }; one = 1; two = 2; }", PrintOptions { .maxDepth = 2 });
test(vNested, "{ nested = { nested = { }; one = 1; two = 2; }; one = 1; two = 2; }", PrintOptions { .maxDepth = 3 });
test(vNested, "{ nested = { nested = { }; one = 1; two = 2; }; one = 1; two = 2; }", PrintOptions { .maxDepth = 4 });
}
TEST_F(ValuePrintingTests, depthList)
{
Value vOne;
vOne.mkInt(1);
Value vTwo;
vTwo.mkInt(2);
BindingsBuilder builder(state, state.allocBindings(10));
builder.insert(state.symbols.create("one"), &vOne);
builder.insert(state.symbols.create("two"), &vTwo);
Value vAttrs;
vAttrs.mkAttrs(builder.finish());
BindingsBuilder builder2(state, state.allocBindings(10));
builder2.insert(state.symbols.create("one"), &vOne);
builder2.insert(state.symbols.create("two"), &vTwo);
builder2.insert(state.symbols.create("nested"), &vAttrs);
Value vNested;
vNested.mkAttrs(builder2.finish());
Value vList;
state.mkList(vList, 5);
vList.bigList.elems[0] = &vOne;
vList.bigList.elems[1] = &vTwo;
vList.bigList.elems[2] = &vNested;
vList.bigList.size = 3;
test(vList, "[ 1 2 { ... } ]", PrintOptions { .maxDepth = 1 });
test(vList, "[ 1 2 { nested = { ... }; one = 1; two = 2; } ]", PrintOptions { .maxDepth = 2 });
test(vList, "[ 1 2 { nested = { one = 1; two = 2; }; one = 1; two = 2; } ]", PrintOptions { .maxDepth = 3 });
test(vList, "[ 1 2 { nested = { one = 1; two = 2; }; one = 1; two = 2; } ]", PrintOptions { .maxDepth = 4 });
test(vList, "[ 1 2 { nested = { one = 1; two = 2; }; one = 1; two = 2; } ]", PrintOptions { .maxDepth = 5 });
}
struct StringPrintingTests : LibExprTest
{
template<class... A>
void test(std::string_view literal, std::string_view expected, unsigned int maxLength, A... args)
{
Value v;
v.mkString(literal);
std::stringstream out;
printValue(state, out, v, PrintOptions {
.maxStringLength = maxLength
});
ASSERT_EQ(out.str(), expected);
}
};
TEST_F(StringPrintingTests, maxLengthTruncation)
{
test("abcdefghi", "\"abcdefghi\"", 10);
test("abcdefghij", "\"abcdefghij\"", 10);
test("abcdefghijk", "\"abcdefghij\" «1 byte elided»", 10);
test("abcdefghijkl", "\"abcdefghij\" «2 bytes elided»", 10);
test("abcdefghijklm", "\"abcdefghij\" «3 bytes elided»", 10);
}
// Check that printing an attrset shows 'important' attributes like `type`
// first, but only reorder the attrs when we have a maxAttrs budget.
TEST_F(ValuePrintingTests, attrsTypeFirst)
{
Value vType;
vType.mkString("puppy");
Value vApple;
vApple.mkString("apple");
BindingsBuilder builder(state, state.allocBindings(10));
builder.insert(state.symbols.create("type"), &vType);
builder.insert(state.symbols.create("apple"), &vApple);
Value vAttrs;
vAttrs.mkAttrs(builder.finish());
test(vAttrs,
"{ type = \"puppy\"; apple = \"apple\"; }",
PrintOptions {
.maxAttrs = 100
});
test(vAttrs,
"{ apple = \"apple\"; type = \"puppy\"; }",
PrintOptions { });
}
TEST_F(ValuePrintingTests, ansiColorsInt)
{
Value v;
v.mkInt(10);
test(v,
ANSI_CYAN "10" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsFloat)
{
Value v;
v.mkFloat(1.6);
test(v,
ANSI_CYAN "1.6" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsBool)
{
Value v;
v.mkBool(true);
test(v,
ANSI_CYAN "true" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsString)
{
Value v;
v.mkString("puppy");
test(v,
ANSI_MAGENTA "\"puppy\"" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsStringElided)
{
Value v;
v.mkString("puppy");
test(v,
ANSI_MAGENTA "\"pup\"" ANSI_FAINT " «2 bytes elided»" ANSI_NORMAL,
PrintOptions {
.ansiColors = true,
.maxStringLength = 3
});
}
TEST_F(ValuePrintingTests, ansiColorsPath)
{
Value v;
v.mkPath(state.rootPath(CanonPath("puppy")));
test(v,
ANSI_GREEN "/puppy" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsNull)
{
Value v;
v.mkNull();
test(v,
ANSI_CYAN "null" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsAttrs)
{
Value vOne;
vOne.mkInt(1);
Value vTwo;
vTwo.mkInt(2);
BindingsBuilder builder(state, state.allocBindings(10));
builder.insert(state.symbols.create("one"), &vOne);
builder.insert(state.symbols.create("two"), &vTwo);
Value vAttrs;
vAttrs.mkAttrs(builder.finish());
test(vAttrs,
"{ one = " ANSI_CYAN "1" ANSI_NORMAL "; two = " ANSI_CYAN "2" ANSI_NORMAL "; }",
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsDerivation)
{
Value vDerivation;
vDerivation.mkString("derivation");
BindingsBuilder builder(state, state.allocBindings(10));
builder.insert(state.sType, &vDerivation);
Value vAttrs;
vAttrs.mkAttrs(builder.finish());
test(vAttrs,
ANSI_GREEN "«derivation»" ANSI_NORMAL,
PrintOptions {
.ansiColors = true,
.force = true,
.derivationPaths = true
});
test(vAttrs,
"{ type = " ANSI_MAGENTA "\"derivation\"" ANSI_NORMAL "; }",
PrintOptions {
.ansiColors = true,
.force = true
});
}
TEST_F(ValuePrintingTests, ansiColorsError)
{
Value throw_ = state.getBuiltin("throw");
Value message;
message.mkString("uh oh!");
Value vError;
vError.mkApp(&throw_, &message);
test(vError,
ANSI_RED
"«"
ANSI_RED
"error:"
ANSI_NORMAL
"\n … while calling the '"
ANSI_MAGENTA
"throw"
ANSI_NORMAL
"' builtin\n\n "
ANSI_RED
"error:"
ANSI_NORMAL
" uh oh!»"
ANSI_NORMAL,
PrintOptions {
.ansiColors = true,
.force = true,
});
}
TEST_F(ValuePrintingTests, ansiColorsDerivationError)
{
Value throw_ = state.getBuiltin("throw");
Value message;
message.mkString("uh oh!");
Value vError;
vError.mkApp(&throw_, &message);
Value vDerivation;
vDerivation.mkString("derivation");
BindingsBuilder builder(state, state.allocBindings(10));
builder.insert(state.sType, &vDerivation);
builder.insert(state.sDrvPath, &vError);
Value vAttrs;
vAttrs.mkAttrs(builder.finish());
test(vAttrs,
"{ drvPath = "
ANSI_RED
"«"
ANSI_RED
"error:"
ANSI_NORMAL
"\n … while calling the '"
ANSI_MAGENTA
"throw"
ANSI_NORMAL
"' builtin\n\n "
ANSI_RED
"error:"
ANSI_NORMAL
" uh oh!»"
ANSI_NORMAL
"; type = "
ANSI_MAGENTA
"\"derivation\""
ANSI_NORMAL
"; }",
PrintOptions {
.ansiColors = true,
.force = true
});
test(vAttrs,
ANSI_RED
"«"
ANSI_RED
"error:"
ANSI_NORMAL
"\n … while calling the '"
ANSI_MAGENTA
"throw"
ANSI_NORMAL
"' builtin\n\n "
ANSI_RED
"error:"
ANSI_NORMAL
" uh oh!»"
ANSI_NORMAL,
PrintOptions {
.ansiColors = true,
.force = true,
.derivationPaths = true,
});
}
TEST_F(ValuePrintingTests, ansiColorsAssert)
{
ExprVar eFalse(state.symbols.create("false"));
eFalse.bindVars(state, state.staticBaseEnv);
ExprInt eInt(1);
ExprAssert expr(noPos, &eFalse, &eInt);
Value v;
state.mkThunk_(v, &expr);
test(v,
ANSI_RED "«" ANSI_RED "error:" ANSI_NORMAL " assertion '" ANSI_MAGENTA "false" ANSI_NORMAL "' failed»" ANSI_NORMAL,
PrintOptions {
.ansiColors = true,
.force = true
});
}
TEST_F(ValuePrintingTests, ansiColorsList)
{
Value vOne;
vOne.mkInt(1);
Value vTwo;
vTwo.mkInt(2);
Value vList;
state.mkList(vList, 5);
vList.bigList.elems[0] = &vOne;
vList.bigList.elems[1] = &vTwo;
vList.bigList.size = 3;
test(vList,
"[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_CYAN "2" ANSI_NORMAL " " ANSI_MAGENTA "«nullptr»" ANSI_NORMAL " ]",
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsLambda)
{
Env env {
.up = nullptr,
.values = { }
};
PosTable::Origin origin((std::monostate()));
auto posIdx = state.positions.add(origin, 1, 1);
auto body = ExprInt(0);
auto formals = Formals {};
ExprLambda eLambda(posIdx, createSymbol("a"), &formals, &body);
Value vLambda;
vLambda.mkLambda(&env, &eLambda);
test(vLambda,
ANSI_BLUE "«lambda @ «none»:1:1»" ANSI_NORMAL,
PrintOptions {
.ansiColors = true,
.force = true
});
eLambda.setName(createSymbol("puppy"));
test(vLambda,
ANSI_BLUE "«lambda puppy @ «none»:1:1»" ANSI_NORMAL,
PrintOptions {
.ansiColors = true,
.force = true
});
}
TEST_F(ValuePrintingTests, ansiColorsPrimOp)
{
PrimOp primOp{
.name = "puppy"
};
Value v;
v.mkPrimOp(&primOp);
test(v,
ANSI_BLUE "«primop puppy»" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsPrimOpApp)
{
PrimOp primOp{
.name = "puppy"
};
Value vPrimOp;
vPrimOp.mkPrimOp(&primOp);
Value v;
v.mkPrimOpApp(&vPrimOp, nullptr);
test(v,
ANSI_BLUE "«partially applied primop puppy»" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsThunk)
{
Value v;
v.mkThunk(nullptr, nullptr);
test(v,
ANSI_MAGENTA "«thunk»" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsBlackhole)
{
Value v;
v.mkBlackhole();
test(v,
ANSI_RED "«potential infinite recursion»" ANSI_NORMAL,
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsAttrsRepeated)
{
BindingsBuilder emptyBuilder(state, state.allocBindings(1));
Value vEmpty;
vEmpty.mkAttrs(emptyBuilder.finish());
BindingsBuilder builder(state, state.allocBindings(10));
builder.insert(state.symbols.create("a"), &vEmpty);
builder.insert(state.symbols.create("b"), &vEmpty);
Value vAttrs;
vAttrs.mkAttrs(builder.finish());
test(vAttrs,
"{ a = { }; b = " ANSI_MAGENTA "«repeated»" ANSI_NORMAL "; }",
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, ansiColorsListRepeated)
{
BindingsBuilder emptyBuilder(state, state.allocBindings(1));
Value vEmpty;
vEmpty.mkAttrs(emptyBuilder.finish());
Value vList;
state.mkList(vList, 3);
vList.bigList.elems[0] = &vEmpty;
vList.bigList.elems[1] = &vEmpty;
vList.bigList.size = 2;
test(vList,
"[ { } " ANSI_MAGENTA "«repeated»" ANSI_NORMAL " ]",
PrintOptions {
.ansiColors = true
});
}
TEST_F(ValuePrintingTests, listRepeated)
{
BindingsBuilder emptyBuilder(state, state.allocBindings(1));
Value vEmpty;
vEmpty.mkAttrs(emptyBuilder.finish());
Value vList;
state.mkList(vList, 3);
vList.bigList.elems[0] = &vEmpty;
vList.bigList.elems[1] = &vEmpty;
vList.bigList.size = 2;
test(vList, "[ { } «repeated» ]", PrintOptions { });
test(vList,
"[ { } { } ]",
PrintOptions {
.trackRepeated = false
});
}
TEST_F(ValuePrintingTests, ansiColorsAttrsElided)
{
Value vOne;
vOne.mkInt(1);
Value vTwo;
vTwo.mkInt(2);
BindingsBuilder builder(state, state.allocBindings(10));
builder.insert(state.symbols.create("one"), &vOne);
builder.insert(state.symbols.create("two"), &vTwo);
Value vAttrs;
vAttrs.mkAttrs(builder.finish());
test(vAttrs,
"{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT " «1 attribute elided»" ANSI_NORMAL "}",
PrintOptions {
.ansiColors = true,
.maxAttrs = 1
});
Value vThree;
vThree.mkInt(3);
builder.insert(state.symbols.create("three"), &vThree);
vAttrs.mkAttrs(builder.finish());
test(vAttrs,
"{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT " «2 attributes elided»" ANSI_NORMAL "}",
PrintOptions {
.ansiColors = true,
.maxAttrs = 1
});
}
TEST_F(ValuePrintingTests, ansiColorsListElided)
{
BindingsBuilder emptyBuilder(state, state.allocBindings(1));
Value vOne;
vOne.mkInt(1);
Value vTwo;
vTwo.mkInt(2);
Value vList;
state.mkList(vList, 4);
vList.bigList.elems[0] = &vOne;
vList.bigList.elems[1] = &vTwo;
vList.bigList.size = 2;
test(vList,
"[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT " «1 item elided»" ANSI_NORMAL "]",
PrintOptions {
.ansiColors = true,
.maxListItems = 1
});
Value vThree;
vThree.mkInt(3);
vList.bigList.elems[2] = &vThree;
vList.bigList.size = 3;
test(vList,
"[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT " «2 items elided»" ANSI_NORMAL "]",
PrintOptions {
.ansiColors = true,
.maxListItems = 1
});
}
} // namespace nix