From 6e99b8dadbcc2b2f46c4261a3214ffc08ed9dc50 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Fri, 25 Jun 2021 16:36:25 -0700
Subject: [PATCH 1/2] Forbid duplicate tests only in compiler runner

Not in fourslash, user, docker, etc.
---
 src/testRunner/runner.ts | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/testRunner/runner.ts b/src/testRunner/runner.ts
index 0c5561332d656..35220f12f9fb5 100644
--- a/src/testRunner/runner.ts
+++ b/src/testRunner/runner.ts
@@ -9,15 +9,16 @@ namespace Harness {
             const seen = new Map<string, string>();
             const dupes: [string, string][] = [];
             for (const runner of runners) {
-                for (const sf of runner.enumerateTestFiles()) {
-                    const full = typeof sf === "string" ? sf : sf.file;
-                    const base = vpath.basename(full).toLowerCase();
-                    // exempt fourslash-fourslash conflicts since they're less likely to emit baselines
-                    if (seen.has(base) && !(/fourslash/.test(seen.get(base)!) && /fourslash/.test(full))) {
-                        dupes.push([seen.get(base)!, full]);
-                    }
-                    else {
-                        seen.set(base, full);
+                if (runner instanceof CompilerBaselineRunner) {
+                    for (const sf of runner.enumerateTestFiles()) {
+                        const full = typeof sf === "string" ? sf : sf.file;
+                        const base = vpath.basename(full).toLowerCase();
+                        if (seen.has(base)) {
+                            dupes.push([seen.get(base)!, full]);
+                        }
+                        else {
+                            seen.set(base, full);
+                        }
                     }
                 }
                 runner.initializeTests();

From 3a69eba631fefc2f084b441ca69a83991adb9280 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Fri, 25 Jun 2021 16:55:47 -0700
Subject: [PATCH 2/2] Include fourslash, but exempt shims and server

---
 src/testRunner/runner.ts | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/testRunner/runner.ts b/src/testRunner/runner.ts
index 35220f12f9fb5..4427390d7f398 100644
--- a/src/testRunner/runner.ts
+++ b/src/testRunner/runner.ts
@@ -9,11 +9,12 @@ namespace Harness {
             const seen = new Map<string, string>();
             const dupes: [string, string][] = [];
             for (const runner of runners) {
-                if (runner instanceof CompilerBaselineRunner) {
+                if (runner instanceof CompilerBaselineRunner || runner instanceof FourSlashRunner) {
                     for (const sf of runner.enumerateTestFiles()) {
                         const full = typeof sf === "string" ? sf : sf.file;
                         const base = vpath.basename(full).toLowerCase();
-                        if (seen.has(base)) {
+                        // allow existing dupes in fourslash/shims and fourslash/server
+                        if (seen.has(base) && !/fourslash\/(shim|server)/.test(full)) {
                             dupes.push([seen.get(base)!, full]);
                         }
                         else {