microsoft · Jake Bailey (jakebailey) · Sep 8, 2026
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -142,8 +142,6 @@ jobs:
           echo "::remove-matcher owner=tsc::"
           echo "::remove-matcher owner=go::"
       - run: npm ci
-      - run: go install gotest.tools/gotestsum@latest
-        if: ${{ matrix.config.os != 'windows' && !matrix.config.race }}
       - name: Tests
         id: test
         run: npx hereby test:tsc
@@ -213,8 +211,6 @@ jobs:
           echo "::remove-matcher owner=tsc::"
           echo "::remove-matcher owner=go::"
       - run: npm ci
-      - run: go install gotest.tools/gotestsum@latest
-        if: ${{ matrix.config.os != 'windows' }}
       - run: npx hereby test:extension
       - run: npx hereby test:tools
       - run: npx hereby test:api

diff --git a/Herebyfile.mjs b/Herebyfile.mjs
@@ -226,21 +226,6 @@ async function runWithConcurrencyLimit(tasks, concurrency) {
     }
 }
 
-const tools = new Map([
-    ["gotest.tools/gotestsum", "latest"],
-]);
-
-const hasGotestsum = memoize(() => {
-    try {
-        return xSync("gotestsum", ["--version"], {
-            nodeOptions: { stdio: "ignore" },
-        }).exitCode === 0;
-    }
-    catch {
-        return false;
-    }
-});
-
 const builtLocal = "./built/local";
 
 const libsDir = "./tsc/internal/bundled/libs";
@@ -1014,14 +999,15 @@ const ensureCoverageDirExists = memoize(() => {
 
 /**
  * @param {string} taskName
+ * @param {string} packagePattern
  */
-function goTestFlags(taskName) {
+function goTestFlags(taskName, packagePattern = "./...") {
     ensureCoverageDirExists();
     return [
         ...goBuildFlags,
         ...goBuildTags(),
         ...(options.tests ? [`-run=${options.tests}`] : []),
-        ...(options.coverage ? [`-coverprofile=${path.join(coverageDir, "coverage." + taskName + ".out")}`, "-coverpkg=./..."] : []),
+        ...(options.coverage ? [`-coverprofile=${path.join(coverageDir, "coverage." + taskName + ".out")}`, `-coverpkg=${packagePattern}`] : []),
     ];
 }
 
@@ -1103,10 +1089,20 @@ async function checkUnusedBaselines(trackingDir) {
 
 /**
  * @param {string} taskName
+ * @param {string} packagePattern
+ * @param {string} [toolModfile]
  */
-function gotestsum(taskName) {
-    const args = hasGotestsum() ? ["gotestsum", ...goTestSumFlags, "--"] : ["go", "test"];
-    return args.concat(goTestFlags(taskName));
+function gotestsum(taskName, packagePattern, toolModfile) {
+    return [
+        "go",
+        "tool",
+        ...(toolModfile ? [`-modfile=${toolModfile}`] : []),
+        "gotestsum",
+        ...goTestSumFlags,
+        "--",
+        ...goTestFlags(taskName, packagePattern),
+        packagePattern,
+    ];
 }
 
 /**
@@ -1137,10 +1133,11 @@ async function runTests() {
     try {
         const testEnv = {
             ...goTestEnv,
+            GOWORK: "off",
             ...(trackingDir ? { TSGO_BASELINE_TRACKING_DIR: trackingDir } : {}),
         };
-        const command = gotestsum("tests");
-        await run(command[0], [...command.slice(1), "./...", ...(isCI ? ["--timeout=45m"] : [])], {
+        const command = gotestsum("tests", "./...", "../tools/go.mod");
+        await run(command[0], [...command.slice(1), ...(isCI ? ["--timeout=45m"] : [])], {
             env: testEnv,
             cwd: "./tsc",
         });
@@ -1208,8 +1205,8 @@ export const testBenchmarks = task({
 });
 
 async function runTestTools() {
-    const command = gotestsum("tools");
-    await run(command[0], [...command.slice(1), "./..."], { env: goTestEnv, cwd: path.join(__dirname, "tools") });
+    const command = gotestsum("tools", "./...");
+    await run(command[0], command.slice(1), { env: goTestEnv, cwd: path.join(__dirname, "tools") });
 }
 
 async function runTestAPI() {
@@ -1346,12 +1343,7 @@ async function runLint() {
 export const installTools = task({
     name: "install-tools",
     description: "Installs optional tools for developing within the repo.",
-    run: async () => {
-        await Promise.all([
-            ...[...tools].map(([tool, version]) => run("go", ["install", tool + (version ? `@${version}` : "")])),
-            buildCustomLinter(),
-        ]);
-    },
+    run: buildCustomLinter,
 });
 
 export const format = task({

diff --git a/tools/go.mod b/tools/go.mod
@@ -14,14 +14,27 @@ require (
 require (
 	github.com/anchore/go-logger v0.0.0-20251106021608-a5b0513fa9a9 // indirect
 	github.com/anchore/go-macholibre v0.0.0-20250826193721-3cd206ca93aa // indirect
+	github.com/bitfield/gotestdox v0.2.2 // indirect
 	github.com/blacktop/go-dwarf v1.0.14 // indirect
+	github.com/dnephin/pflag v1.0.7 // indirect
+	github.com/fatih/color v1.18.0 // indirect
+	github.com/fsnotify/fsnotify v1.9.0 // indirect
 	github.com/github/smimesign v0.2.0 // indirect
 	github.com/go-restruct/restruct v1.2.0-alpha // indirect
 	github.com/google/go-cmp v0.7.0 // indirect
+	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
 	github.com/google/uuid v1.6.0 // indirect
+	github.com/mattn/go-colorable v0.1.14 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/scylladb/go-set v1.0.3-0.20200225121959-cc7b2070d91e // indirect
 	golang.org/x/crypto v0.53.0 // indirect
 	golang.org/x/sync v0.21.0 // indirect
+	golang.org/x/sys v0.46.0 // indirect
+	golang.org/x/term v0.44.0 // indirect
+	golang.org/x/text v0.38.0 // indirect
+	gotest.tools/gotestsum v1.13.0 // indirect
 	software.sslmate.com/src/go-pkcs12 v0.7.2 // indirect
 )
+
+tool gotest.tools/gotestsum
diff --git a/tools/go.sum b/tools/go.sum
@@ -6,6 +6,8 @@ github.com/anchore/go-macholibre v0.0.0-20250826193721-3cd206ca93aa h1:KPEP8f3en
 github.com/anchore/go-macholibre v0.0.0-20250826193721-3cd206ca93aa/go.mod h1:7YJA6tAfRm4SzIF93b32pR4xnbf8g2nJIeQnp+2vzzI=
 github.com/anchore/quill v0.7.1 h1:/K2Yvcjs3ipmP+hjxXmy+3IL/nZ0Tnj8S+OLZvtXRYI=
 github.com/anchore/quill v0.7.1/go.mod h1:1ExdNP//bdjTRROE/MJg8MxLoDzIJH5HvsbMW4chpBo=
+github.com/bitfield/gotestdox v0.2.2 h1:x6RcPAbBbErKLnapz1QeAlf3ospg8efBsedU93CDsnE=
+github.com/bitfield/gotestdox v0.2.2/go.mod h1:D+gwtS0urjBrzguAkTM2wodsTQYFHdpx8eqRJ3N+9pY=
 github.com/blacktop/go-dwarf v1.0.14 h1:OjmzfSgg/qAKckn2tWFebcgKgJ7HOqCj7bS+CiE1lrY=
 github.com/blacktop/go-dwarf v1.0.14/go.mod h1:4W2FKgSFYcZLDwnR7k+apv5i3nrau4NGl9N6VQ9DSTo=
 github.com/blacktop/go-macho v1.1.263 h1:wzcLdip1PD2UwOZ5liKijF4YlYbFFF7XdqjLp3VQ1d0=
@@ -15,8 +17,14 @@ github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dnephin/pflag v1.0.7 h1:oxONGlWxhmUct0YzKTgrpQv9AUA1wtPBn7zuSjJqptk=
+github.com/dnephin/pflag v1.0.7/go.mod h1:uxE91IoWURlOiTUIA8Mq5ZZkAv3dPUfZNaT80Zm7OQE=
+github.com/fatih/color v1.18.0 h1:S8gINlzdQ840/4pfAwic/ZE0djQEH3wM94VfqLTZcOM=
+github.com/fatih/color v1.18.0/go.mod h1:4FelSpRwEGDpQ12mAdzqdOukCy4u8WUtOY6lkT/6HfU=
 github.com/fatih/set v0.2.1 h1:nn2CaJyknWE/6txyUDGwysr3G5QC6xWB/PtVjPBbeaA=
 github.com/fatih/set v0.2.1/go.mod h1:+RKtMCH+favT2+3YecHGxcc0b4KyVWA1QWWJUs4E0CI=
+github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
+github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
 github.com/github/smimesign v0.2.0 h1:Hho4YcX5N1I9XNqhq0fNx0Sts8MhLonHd+HRXVGNjvk=
 github.com/github/smimesign v0.2.0/go.mod h1:iZiiwNT4HbtGRVqCQu7uJPEZCuEE5sfSSttcnePkDl4=
 github.com/go-restruct/restruct v1.2.0-alpha h1:2Lp474S/9660+SJjpVxoKuWX09JsXHSrdV7Nv3/gkvc=
@@ -25,6 +33,8 @@ github.com/golangci/plugin-module-register v0.1.2 h1:e5WM6PO6NIAEcij3B053CohVp3H
 github.com/golangci/plugin-module-register v0.1.2/go.mod h1:1+QGTsKBvAIvPvoY/os+G5eoqxWn70HYDm2uvUyGuVw=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE=
@@ -40,6 +50,8 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.11.0 h1:cWPaGQEPrBb5/AsnsZesgZZ9yb1OQ+GOISoDNXVBh4M=
+github.com/rogpeppe/go-internal v1.11.0/go.mod h1:ddIwULY96R17DhadqLgMfk9H9tvdUzkipdSkR5nkCZA=
 github.com/scylladb/go-set v1.0.3-0.20200225121959-cc7b2070d91e h1:7q6NSFZDeGfvvtIRwBrU/aegEYJYmvev0cHAwo17zZQ=
 github.com/scylladb/go-set v1.0.3-0.20200225121959-cc7b2070d91e/go.mod h1:DkpGd78rljTxKAnTDPFqXSGxvETQnJyuSOQwsHycqfs=
 github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
@@ -60,11 +72,14 @@ golang.org/x/sync v0.21.0 h1:HLII4xRRTtCRkxYp4HNFF0Js/Og6q2i++KXbg0gHCwM=
 golang.org/x/sync v0.21.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.46.0 h1:noSf2Fq6F8DBgS+LysIkx7rIExoNHJsxOAtPp4rthXw=
 golang.org/x/sys v0.46.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/term v0.44.0 h1:0rLvDRCtNj0gZkyIXhCyOb2OAzEhLVqc4B+hrsBhrmc=
 golang.org/x/term v0.44.0/go.mod h1:7ze4MdzUzLXpSAoFP1H0bOI9aXDqveSvatT5vKcFh2Y=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.38.0 h1:sXmwo9DwP3OK9EZ7PqAdaooSGozfl/3a6/xJcbzPRhE=
+golang.org/x/text v0.38.0/go.mod h1:YXZt3QhHUKYT53r2lLKFIVi6Ao1jdzrTR/KQ09qyxF4=
 golang.org/x/tools v0.47.0 h1:7Kn5x/d1svx/PzryTsqeoZN4TZwqeH5pGWjefhLi/1Q=
 golang.org/x/tools v0.47.0/go.mod h1:dFHnyTvFWY212G+h7ZY4Vsp/K3U4/7W9TyVaAul8uCA=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
@@ -73,6 +88,8 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gotest.tools/gotestsum v1.13.0 h1:+Lh454O9mu9AMG1APV4o0y7oDYKyik/3kBOiCqiEpRo=
+gotest.tools/gotestsum v1.13.0/go.mod h1:7f0NS5hFb0dWr4NtcsAsF0y1kzjEFfAil0HiBQJE03Q=
 gotest.tools/v3 v3.5.2 h1:7koQfIKdy+I8UTetycgUqXWSDwpgv193Ka+qRsmBY8Q=
 gotest.tools/v3 v3.5.2/go.mod h1:LtdLGcnqToBH83WByAAi/wiwSFCArdFIUV/xxN4pcjA=
 software.sslmate.com/src/go-pkcs12 v0.7.2 h1:Rh9FoMaI5k7Oo6EOS+2/BnoZ+JFIS+XHjM0VGkSPXLM=