Neotest diagnostics

lua/neotest-rust/errors.lua

@@ -0,0 +1,20 @@
+local M = {}
+
+--- Parse errors from rustc output
+---@param output string
+---@return neotest.Error[]
+function M.parse_errors(output)
+    local message, line = output:match("thread '[^']+' panicked at '([^']+)', [^:]+:(%d+):%d+")
+
+    -- If we can't parse the output, return an empty table
+    if message == nil then
+        return {}
+    end
+
+    -- Note: we have to return the line index, not the line number
+    return {
+        { line = tonumber(line) - 1, message = message },
+    }
+end
+
+return M

lua/neotest-rust/init.lua

@@ -2,6 +2,7 @@ local async = require("neotest.async")
 local context_manager = require("plenary.context_manager")
 local dap = require("neotest-rust.dap")
 local util = require("neotest-rust.util")
+local errors = require("neotest-rust.errors")
 local Job = require("plenary.job")
 local open = context_manager.open
 local Path = require("plenary.path")
@@ -371,9 +372,12 @@ function adapter.results(spec, result, tree)
             end
             for _, testcase in pairs(testcases) do
                 if testcase.failure then
+                    local output = testcase.failure[1]
+
                     results[testcase._attr.name] = {
                         status = "failed",
-                        short = testcase.failure[1],
+                        short = output,
+                        errors = errors.parse_errors(output),
                     }
                 else
                     results[testcase._attr.name] = {
@@ -385,9 +389,11 @@ function adapter.results(spec, result, tree)
     elseif spec.context.strategy == "dap" and util.file_exists(output_path) then
         results = dap.translate_results(output_path)
     else
+        local output = result.output
+
         results[spec.context.position_id] = {
             status = "failed",
-            output = result.output,
+            output = output,
         }
     end
 

tests/errors_spec.lua

@@ -0,0 +1,30 @@
+local errors = require("neotest-rust.errors")
+
+describe("parses errors from output", function()
+    it("non-parsable errors in output", function()
+        local output = "something\nwent\nwrong"
+        local results = errors.parse_errors(output)
+
+        assert.is_true(#results == 0)
+    end)
+
+    it("assert_eq", function()
+        local output = "test tests::failed_math ... FAILED\n"
+            .. "failures:\n\n"
+            .. "---- tests::failed_math stdout ----\n"
+            .. "thread 'tests::failed_math' panicked at 'assertion failed: `(left == right)`\n"
+            .. "  left: `2`,\n"
+            .. " right: `3`', src/main.rs:16:9\n"
+            .. "note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace"
+
+        local results = errors.parse_errors(output)
+        local expected = {
+            {
+                line = 15,
+                message = "assertion failed: `(left == right)`\n  left: `2`,\n right: `3`",
+            },
+        }
+
+        assert.are.same(expected, results)
+    end)
+end)

tests/init_spec.lua

@@ -969,6 +969,12 @@ describe("results", function()
             ["foo::tests::should_fail"] = {
                 short = "thread 'foo::tests::should_fail' panicked at 'assertion failed: false', src/foo.rs:10:9\nnote: run with `RUST_BACKTRACE=1` environment variable to display a backtrace",
                 status = "failed",
+                errors = {
+                    {
+                        line = 9,
+                        message = "assertion failed: false",
+                    },
+                },
             },
             ["foo::tests::should_pass"] = {
                 status = "passed",
@@ -990,13 +996,15 @@ describe("results", function()
             ["foo::tests::should_fail"] = {
                 short = "thread 'foo::tests::should_fail' panicked at 'assertion failed: false', src/foo.rs:10:9\nnote: run with `RUST_BACKTRACE=1` environment variable to display a backtrace",
                 status = "failed",
+                errors = { { line = 9, message = "assertion failed: false" } },
             },
             ["foo::tests::should_pass"] = {
                 status = "passed",
             },
             should_fail = {
                 short = "thread 'should_fail' panicked at 'assertion failed: false', tests/tests.rs:8:5\nnote: run with `RUST_BACKTRACE=1` environment variable to display a backtrace",
                 status = "failed",
+                errors = { { line = 7, message = "assertion failed: false" } },
             },
             should_pass = {
                 status = "passed",