Merge pull request #9754 from 9999years/print-value-when-coercion-fails

Print the value in `error: cannot coerce` messages

(cherry picked from commit 5b7bfd2d6b89d7dd5f54c1ca6c8072358d31a84e)

===

test taken from 6e8d5983143ae576e3f4b1d2954a5267f2943a49; it was added
previously (and not backported because its pr was a mostly-revert), but
it's useful to have around.

Change-Id: Icbd14b55e3610ce7b774667bf14b82e6dc717982

2 files changed, 19 insertions, 19 deletions

diff --git a/tests/unit/libexpr/error_traces.cc b/tests/unit/libexpr/error_traces.cc
index 31b9e301d..1d56a8e1e 100644
--- a/tests/unit/libexpr/error_traces.cc
+++ b/tests/unit/libexpr/error_traces.cc
@@ -295,7 +295,7 @@ namespace nix {
     TEST_F(ErrorTraceTest, toPath) {
         ASSERT_TRACE2("toPath []",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a list"),
+                      hintfmt("cannot coerce %s to a string: %s", "a list", "[ ]"),
                       hintfmt("while evaluating the first argument passed to builtins.toPath"));
 
         ASSERT_TRACE2("toPath \"foo\"",
@@ -309,7 +309,7 @@ namespace nix {
     TEST_F(ErrorTraceTest, storePath) {
         ASSERT_TRACE2("storePath true",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a Boolean"),
+                      hintfmt("cannot coerce %s to a string: %s", "a Boolean", ANSI_CYAN "true" ANSI_NORMAL),
                       hintfmt("while evaluating the first argument passed to builtins.storePath"));
 
     }
@@ -318,7 +318,7 @@ namespace nix {
     TEST_F(ErrorTraceTest, pathExists) {
         ASSERT_TRACE2("pathExists []",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a list"),
+                      hintfmt("cannot coerce %s to a string: %s", "a list", "[ ]"),
                       hintfmt("while realising the context of a path"));
 
         ASSERT_TRACE2("pathExists \"zorglub\"",
@@ -332,7 +332,7 @@ namespace nix {
     TEST_F(ErrorTraceTest, baseNameOf) {
         ASSERT_TRACE2("baseNameOf []",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a list"),
+                      hintfmt("cannot coerce %s to a string: %s", "a list", "[ ]"),
                       hintfmt("while evaluating the first argument passed to builtins.baseNameOf"));
 
     }
@@ -377,7 +377,7 @@ namespace nix {
     TEST_F(ErrorTraceTest, filterSource) {
         ASSERT_TRACE2("filterSource [] []",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a list"),
+                      hintfmt("cannot coerce %s to a string: %s", "a list", "[ ]"),
                       hintfmt("while evaluating the second argument (the path to filter) passed to builtins.filterSource"));
 
         ASSERT_TRACE2("filterSource [] \"foo\"",
@@ -1038,7 +1038,7 @@ namespace nix {
     TEST_F(ErrorTraceTest, toString) {
         ASSERT_TRACE2("toString { a = 1; }",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a set"),
+                      hintfmt("cannot coerce %s to a string: %s", "a set", "{ a = " ANSI_CYAN "1" ANSI_NORMAL "; }"),
                       hintfmt("while evaluating the first argument passed to builtins.toString"));
 
     }
@@ -1057,7 +1057,7 @@ namespace nix {
 
         ASSERT_TRACE2("substring 0 3 {}",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a set"),
+                      hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"),
                       hintfmt("while evaluating the third argument (the string) passed to builtins.substring"));
 
         ASSERT_TRACE1("substring (-3) 3 \"sometext\"",
@@ -1070,7 +1070,7 @@ namespace nix {
     TEST_F(ErrorTraceTest, stringLength) {
         ASSERT_TRACE2("stringLength {} # TODO: context is missing ???",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a set"),
+                      hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"),
                       hintfmt("while evaluating the argument passed to builtins.stringLength"));
 
     }
@@ -1143,7 +1143,7 @@ namespace nix {
 
         ASSERT_TRACE2("concatStringsSep \"foo\" [ 1 2 {} ] # TODO: coerce to string is buggy",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "an integer"),
+                      hintfmt("cannot coerce %s to a string: %s", "an integer", ANSI_CYAN "1" ANSI_NORMAL),
                       hintfmt("while evaluating one element of the list of strings to concat passed to builtins.concatStringsSep"));
 
     }
@@ -1229,12 +1229,12 @@ namespace nix {
 
         ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = {}; }",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a set"),
+                      hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"),
                       hintfmt("while evaluating the attribute 'system' of derivation 'foo'"));
 
         ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = {}; }",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a set"),
+                      hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"),
                       hintfmt("while evaluating the attribute 'outputs' of derivation 'foo'"));
 
         ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = \"drv\"; }",
@@ -1279,17 +1279,17 @@ namespace nix {
 
         ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = \"out\"; args = [ {} ]; }",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a set"),
+                      hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"),
                       hintfmt("while evaluating an element of the argument list"));
 
         ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = \"out\"; args = [ \"a\" {} ]; }",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a set"),
+                      hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"),
                       hintfmt("while evaluating an element of the argument list"));
 
         ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = \"out\"; FOO = {}; }",
                       TypeError,
-                      hintfmt("cannot coerce %s to a string", "a set"),
+                      hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"),
                       hintfmt("while evaluating the attribute 'FOO' of derivation 'foo'"));
 
     }
diff --git a/tests/unit/libexpr/value/print.cc b/tests/unit/libexpr/value/print.cc
index 98131112e..c4264a38d 100644
--- a/tests/unit/libexpr/value/print.cc
+++ b/tests/unit/libexpr/value/print.cc
@@ -370,7 +370,7 @@ TEST_F(ValuePrintingTests, ansiColorsStringElided)
     v.mkString("puppy");
 
     test(v,
-         ANSI_MAGENTA "\"pup\"" ANSI_FAINT " «2 bytes elided»" ANSI_NORMAL,
+         ANSI_MAGENTA "\"pup\" " ANSI_FAINT "«2 bytes elided»" ANSI_NORMAL,
          PrintOptions {
              .ansiColors = true,
              .maxStringLength = 3
@@ -756,7 +756,7 @@ TEST_F(ValuePrintingTests, ansiColorsAttrsElided)
     vAttrs.mkAttrs(builder.finish());
 
     test(vAttrs,
-         "{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT " «1 attribute elided»" ANSI_NORMAL "}",
+         "{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT "«1 attribute elided»" ANSI_NORMAL "}",
          PrintOptions {
              .ansiColors = true,
              .maxAttrs = 1
@@ -769,7 +769,7 @@ TEST_F(ValuePrintingTests, ansiColorsAttrsElided)
     vAttrs.mkAttrs(builder.finish());
 
     test(vAttrs,
-         "{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT " «2 attributes elided»" ANSI_NORMAL "}",
+         "{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT "«2 attributes elided»" ANSI_NORMAL "}",
          PrintOptions {
              .ansiColors = true,
              .maxAttrs = 1
@@ -793,7 +793,7 @@ TEST_F(ValuePrintingTests, ansiColorsListElided)
     vList.bigList.size = 2;
 
     test(vList,
-         "[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT " «1 item elided»" ANSI_NORMAL "]",
+         "[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT "«1 item elided»" ANSI_NORMAL "]",
          PrintOptions {
              .ansiColors = true,
              .maxListItems = 1
@@ -806,7 +806,7 @@ TEST_F(ValuePrintingTests, ansiColorsListElided)
     vList.bigList.size = 3;
 
     test(vList,
-         "[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT " «2 items elided»" ANSI_NORMAL "]",
+         "[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT "«2 items elided»" ANSI_NORMAL "]",
          PrintOptions {
              .ansiColors = true,
              .maxListItems = 1