From 6f7a37c99aa43267f2aae4ade4db840fc344035d Mon Sep 17 00:00:00 2001
From: Ron Buckton <ron.buckton@microsoft.com>
Date: Mon, 20 Aug 2018 17:44:34 -0700
Subject: [PATCH] Added fourslash test

---
 src/compiler/moduleNameResolver.ts            | 60 ++++++++++---------
 src/services/pathCompletions.ts               | 28 ++++++++-
 ...tionForStringLiteralNonrelativeImport13.ts | 36 +++++++++++
 3 files changed, 95 insertions(+), 29 deletions(-)
 create mode 100644 tests/cases/fourslash/completionForStringLiteralNonrelativeImport13.ts

diff --git a/src/compiler/moduleNameResolver.ts b/src/compiler/moduleNameResolver.ts
index d1054579e84..c474226217e 100644
--- a/src/compiler/moduleNameResolver.ts
+++ b/src/compiler/moduleNameResolver.ts
@@ -125,6 +125,34 @@ namespace ts {
         }
     }
 
+    /* @internal */
+    export function getPackageJsonTypesVersionsOverride(typesVersions: MapLike<string>) {
+        const typeScriptVersion = Version.parse(version);
+        let bestVersion: Version | undefined;
+        let bestVersionKey: string | undefined;
+        for (const key in typesVersions) {
+            if (!hasProperty(typesVersions, key)) continue;
+
+            const keyVersion = Version.tryParse(key);
+            if (keyVersion === undefined) {
+                continue;
+            }
+
+            // match the greatest version less than the current TypeScript version
+            if (keyVersion.compareTo(typeScriptVersion) <= 0
+                && (bestVersion === undefined || keyVersion.compareTo(bestVersion) > 0)) {
+                bestVersion = keyVersion;
+                bestVersionKey = key;
+            }
+        }
+
+        if (!bestVersionKey) {
+            return;
+        }
+
+        return { version: bestVersionKey, directory: typesVersions[bestVersionKey] };
+    }
+
     function tryReadPackageJsonTypesVersion(jsonContent: PackageJson, baseDirectory: string, state: ModuleResolutionState): string | undefined {
         if (!hasProperty(jsonContent, "typesVersions")) {
             if (state.traceEnabled) {
@@ -141,36 +169,12 @@ namespace ts {
             return;
         }
 
-        const typeScriptVersion = Version.parse(version);
-        let bestVersion: Version | undefined;
-        let bestVersionKey: string | undefined;
-        for (const key in typesVersions) {
-            if (!hasProperty(typesVersions, key)) continue;
-
-            const keyVersion = Version.tryParse(key);
-            if (keyVersion === undefined) {
-                if (state.traceEnabled) {
-                    // TODO(rbuckton): log
-                }
-                continue;
-            }
-
-            // match the greatest version less than the current TypeScript version
-            if (keyVersion.compareTo(typeScriptVersion) <= 0
-                && (bestVersion === undefined || keyVersion.compareTo(bestVersion) > 0)) {
-                bestVersion = keyVersion;
-                bestVersionKey = key;
-            }
+        const result = getPackageJsonTypesVersionsOverride(typesVersions);
+        if (!result) {
+            return undefined;
         }
 
-        if (!bestVersionKey) {
-            if (state.traceEnabled) {
-                // TODO(rbuckton): log
-            }
-            return;
-        }
-
-        const bestVersionPath = typesVersions[bestVersionKey];
+        const { version: bestVersionKey, directory: bestVersionPath } = result;
         if (!isString(bestVersionPath)) {
             if (state.traceEnabled) {
                 trace(state.host, Diagnostics.Expected_type_of_0_field_in_package_json_to_be_1_got_2, `typesVersion['${bestVersionKey}']`, "string", typeof bestVersionPath);
diff --git a/src/services/pathCompletions.ts b/src/services/pathCompletions.ts
index 3a546573db7..f958163bb14 100644
--- a/src/services/pathCompletions.ts
+++ b/src/services/pathCompletions.ts
@@ -107,10 +107,24 @@ namespace ts.Completions.PathCompletions {
 
         // const absolutePath = normalizeAndPreserveTrailingSlash(isRootedDiskPath(fragment) ? fragment : combinePaths(scriptPath, fragment)); // TODO(rbuckton): should use resolvePaths
         const absolutePath = resolvePath(scriptPath, fragment);
-        const baseDirectory = hasTrailingDirectorySeparator(absolutePath) ? absolutePath : getDirectoryPath(absolutePath);
+        let baseDirectory = hasTrailingDirectorySeparator(absolutePath) ? absolutePath : getDirectoryPath(absolutePath);
         const ignoreCase = !(host.useCaseSensitiveFileNames && host.useCaseSensitiveFileNames());
 
         if (tryDirectoryExists(host, baseDirectory)) {
+            // check for a version redirect
+            const packageJsonPath = findPackageJson(baseDirectory, host);
+            if (packageJsonPath) {
+                const packageJson = readJson(packageJsonPath, host as { readFile: (filename: string) => string | undefined });
+                const typesVersions = (packageJson as any).typesVersions;
+                if (typeof typesVersions === "object") {
+                    const result = getPackageJsonTypesVersionsOverride(typesVersions);
+                    const versionPath = result && result.directory;
+                    if (versionPath) {
+                        baseDirectory = resolvePath(baseDirectory, versionPath);
+                    }
+                }
+            }
+
             // Enumerate the available files if possible
             const files = tryReadDirectory(host, baseDirectory, extensions, /*exclude*/ undefined, /*include*/ ["./*"]);
 
@@ -390,6 +404,18 @@ namespace ts.Completions.PathCompletions {
         return paths;
     }
 
+    function findPackageJson(directory: string, host: LanguageServiceHost): string | undefined {
+        let packageJson: string | undefined;
+        forEachAncestorDirectory(directory, ancestor => {
+            if (ancestor === "node_modules") return true;
+            packageJson = findConfigFile(ancestor, (f) => tryFileExists(host, f), "package.json");
+            if (packageJson) {
+                return true; // break out
+            }
+        });
+        return packageJson;
+    }
+
     function enumerateNodeModulesVisibleToScript(host: LanguageServiceHost, scriptPath: string): ReadonlyArray<string> {
         if (!host.readFile || !host.fileExists) return emptyArray;
 
diff --git a/tests/cases/fourslash/completionForStringLiteralNonrelativeImport13.ts b/tests/cases/fourslash/completionForStringLiteralNonrelativeImport13.ts
new file mode 100644
index 00000000000..db88a272ad5
--- /dev/null
+++ b/tests/cases/fourslash/completionForStringLiteralNonrelativeImport13.ts
@@ -0,0 +1,36 @@
+/// <reference path='fourslash.ts' />
+
+// Should give completions based on typesVersions
+
+// @Filename: node_modules/ext/package.json
+//// {
+////     "name": "ext",
+////     "version": "1.0.0",
+////     "types": "index",
+////     "typesVersions": {
+////         "3.0": "ts3.0"
+////     }
+//// }
+
+// @Filename: node_modules/ext/index.d.ts
+//// export {};
+
+// @Filename: node_modules/ext/aaa.d.ts
+//// export {};
+
+// @Filename: node_modules/ext/ts3.0/index.d.ts
+//// export {};
+
+// @Filename: node_modules/ext/ts3.0/zzz.d.ts
+//// export {};
+
+// @Filename: main.ts
+//// import * as ext1 from "ext//*import_as0*/
+//// import ext2 = require("ext//*import_equals0*/
+//// var ext2 = require("ext//*require0*/
+
+verify.completions({
+    marker: test.markerNames(),
+    exact: ["index", "zzz"],
+    isNewIdentifierLocation: true,
+});