From c67c68e1490aa7248b44fea0aaa189ce13ca430b Mon Sep 17 00:00:00 2001
From: Sheetal Nandi <shkamat@microsoft.com>
Date: Mon, 23 Sep 2019 13:15:40 -0700
Subject: [PATCH] Sort the paths for module specifier by closeness to importing
 file path Fixes #32970

---
 src/compiler/moduleSpecifiers.ts              | 39 ++++++++++++++++++-
 ...gh-source-and-another-symlinked-package.js | 11 +++++-
 2 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/src/compiler/moduleSpecifiers.ts b/src/compiler/moduleSpecifiers.ts
index cd566c0e6e840..fbb832400c24f 100644
--- a/src/compiler/moduleSpecifiers.ts
+++ b/src/compiler/moduleSpecifiers.ts
@@ -186,6 +186,18 @@ namespace ts.moduleSpecifiers {
         return result;
     }
 
+    function numberOfDirectorySeparators(str: string) {
+        const match = str.match(/\//g);
+        return match ? match.length : 0;
+    }
+
+    function comparePathsByNumberOfDirectrorySeparators(a: string, b: string) {
+        return compareValues(
+            numberOfDirectorySeparators(a),
+            numberOfDirectorySeparators(b)
+        );
+    }
+
     /**
      * Looks for existing imports that use symlinks to this module.
      * Symlinks will be returned first so they are preferred over the real path.
@@ -214,7 +226,32 @@ namespace ts.moduleSpecifiers {
             }
         });
         result.push(...targets);
-        return result;
+        if (result.length < 2) return result;
+
+        // Sort by paths closest to importing file Name directory
+        const allFileNames = arrayToMap(result, identity, getCanonicalFileName);
+        const sortedPaths: string[] = [];
+        for (
+            let directory = getDirectoryPath(toPath(importingFileName, cwd, getCanonicalFileName));
+            allFileNames.size !== 0;
+            directory = getDirectoryPath(directory)
+        ) {
+            const directoryStart = ensureTrailingDirectorySeparator(directory);
+            let pathsInDirectory: string[] | undefined;
+            allFileNames.forEach((canonicalFileName, fileName) => {
+                if (startsWith(canonicalFileName, directoryStart)) {
+                    (pathsInDirectory || (pathsInDirectory = [])).push(fileName);
+                    allFileNames.delete(fileName);
+                }
+            });
+            if (pathsInDirectory) {
+                if (pathsInDirectory.length > 1) {
+                    pathsInDirectory.sort(comparePathsByNumberOfDirectrorySeparators);
+                }
+                sortedPaths.push(...pathsInDirectory);
+            }
+        }
+        return sortedPaths;
     }
 
     function tryGetModuleNameFromAmbientModule(moduleSymbol: Symbol): string | undefined {
diff --git a/tests/baselines/reference/tsc/declarationEmit/initial-build/when-same-version-is-referenced-through-source-and-another-symlinked-package.js b/tests/baselines/reference/tsc/declarationEmit/initial-build/when-same-version-is-referenced-through-source-and-another-symlinked-package.js
index ec612b65f170d..5db17df5e9814 100644
--- a/tests/baselines/reference/tsc/declarationEmit/initial-build/when-same-version-is-referenced-through-source-and-another-symlinked-package.js
+++ b/tests/baselines/reference/tsc/declarationEmit/initial-build/when-same-version-is-referenced-through-source-and-another-symlinked-package.js
@@ -1,13 +1,20 @@
 //// [/lib/initial-buildOutput.txt]
 /lib/tsc -p plugin-one --listFiles
-plugin-one/action.ts(4,14): error TS2742: The inferred type of 'actions' cannot be named without a reference to 'plugin-two/node_modules/typescript-fsa'. This is likely not portable. A type annotation is necessary.
 /lib/lib.d.ts
 /plugin-one/node_modules/typescript-fsa/index.d.ts
 /plugin-one/action.ts
 /plugin-two/node_modules/typescript-fsa/index.d.ts -> /plugin-one/node_modules/typescript-fsa/index.d.ts
 /plugin-two/index.d.ts
 /plugin-one/index.ts
-exitCode:: 1
+exitCode:: 0
+
+
+//// [/plugin-one/action.d.ts]
+export declare const actions: {
+    featureOne: import("typescript-fsa").ActionCreator<{
+        route: string;
+    }>;
+};
 
 
 //// [/plugin-one/action.js]