chore: Implement strict mode (denoland/deno_std#453)

Original: https://github.com/denoland/deno_std/commit/be24677d15494e83eea2e99bfc5ccfdde31cb892

5 files changed, 20 insertions, 14 deletions

diff --git a/fs/path/join_test.ts b/fs/path/join_test.ts
index d82a1b471..2c0f35e48 100644
--- a/fs/path/join_test.ts
+++ b/fs/path/join_test.ts
@@ -108,18 +108,21 @@ const windowsJoinTests = [
 
 test(function join() {
   joinTests.forEach(function(p) {
-    const actual = path.posix.join.apply(null, p[0]);
+    const _p = p[0] as string[];
+    const actual = path.posix.join.apply(null, _p);
     assertEquals(actual, p[1]);
   });
 });
 
 test(function joinWin32() {
   joinTests.forEach(function(p) {
-    const actual = path.win32.join.apply(null, p[0]).replace(backslashRE, "/");
+    const _p = p[0] as string[];
+    const actual = path.win32.join.apply(null, _p).replace(backslashRE, "/");
     assertEquals(actual, p[1]);
   });
   windowsJoinTests.forEach(function(p) {
-    const actual = path.win32.join.apply(null, p[0]);
+    const _p = p[0] as string[];
+    const actual = path.win32.join.apply(null, _p);
     assertEquals(actual, p[1]);
   });
 });
diff --git a/fs/path/parse_format_test.ts b/fs/path/parse_format_test.ts
index 05327a139..8829891da 100644
--- a/fs/path/parse_format_test.ts
+++ b/fs/path/parse_format_test.ts
@@ -79,8 +79,8 @@ const unixSpecialCaseFormatTests = [
   [{}, ""]
 ];
 
-function checkParseFormat(path, paths): void {
-  paths.forEach(function(p) {
+function checkParseFormat(path: any, paths: any): void {
+  paths.forEach(function(p: Record<string, unknown>[]) {
     const element = p[0];
     const output = path.parse(element);
     assertEquals(typeof output.root, "string");
@@ -95,8 +95,8 @@ function checkParseFormat(path, paths): void {
   });
 }
 
-function checkSpecialCaseParseFormat(path, testCases): void {
-  testCases.forEach(function(testCase) {
+function checkSpecialCaseParseFormat(path: any, testCases: any): void {
+  testCases.forEach(function(testCase: Record<string, unknown>[]) {
     const element = testCase[0];
     const expect = testCase[1];
     const output = path.parse(element);
@@ -106,7 +106,7 @@ function checkSpecialCaseParseFormat(path, testCases): void {
   });
 }
 
-function checkFormat(path, testCases): void {
+function checkFormat(path: any, testCases: unknown[][]): void {
   testCases.forEach(function(testCase) {
     assertEquals(path.format(testCase[0]), testCase[1]);
   });
diff --git a/fs/path/resolve_test.ts b/fs/path/resolve_test.ts
index 7ee9513c1..606570aad 100644
--- a/fs/path/resolve_test.ts
+++ b/fs/path/resolve_test.ts
@@ -37,14 +37,16 @@ const posixTests =
 
 test(function resolve() {
   posixTests.forEach(function(p) {
-    const actual = path.posix.resolve.apply(null, p[0]);
+    const _p = p[0] as string[];
+    const actual = path.posix.resolve.apply(null, _p);
     assertEquals(actual, p[1]);
   });
 });
 
 test(function resolveWin32() {
   windowsTests.forEach(function(p) {
-    const actual = path.win32.resolve.apply(null, p[0]);
+    const _p = p[0] as string[];
+    const actual = path.win32.resolve.apply(null, _p);
     assertEquals(actual, p[1]);
   });
 });
diff --git a/fs/path/utils.ts b/fs/path/utils.ts
index e50cb6d3c..7a4cd7299 100644
--- a/fs/path/utils.ts
+++ b/fs/path/utils.ts
@@ -49,7 +49,7 @@ export function normalizeString(
   let code: number;
   for (let i = 0, len = path.length; i <= len; ++i) {
     if (i < len) code = path.charCodeAt(i);
-    else if (isPathSeparator(code)) break;
+    else if (isPathSeparator(code!)) break;
     else code = CHAR_FORWARD_SLASH;
 
     if (isPathSeparator(code)) {
@@ -107,7 +107,7 @@ export function _format(
   sep: string,
   pathObject: FormatInputPathObject
 ): string {
-  const dir: string | null = pathObject.dir || pathObject.root;
+  const dir: string | undefined = pathObject.dir || pathObject.root;
   const base: string =
     pathObject.base || (pathObject.name || "") + (pathObject.ext || "");
   if (!dir) return base;
diff --git a/fs/path/win32.ts b/fs/path/win32.ts
index 6b906bc7b..d42cc4885 100644
--- a/fs/path/win32.ts
+++ b/fs/path/win32.ts
@@ -171,7 +171,7 @@ export function normalize(path: string): string {
   const len = path.length;
   if (len === 0) return ".";
   let rootEnd = 0;
-  let device: string;
+  let device: string | undefined;
   let isAbsolute = false;
   const code = path.charCodeAt(0);
 
@@ -301,7 +301,7 @@ export function join(...paths: string[]): string {
   const pathsCount = paths.length;
   if (pathsCount === 0) return ".";
 
-  let joined: string;
+  let joined: string | undefined;
   let firstPart: string;
   for (let i = 0; i < pathsCount; ++i) {
     let path = paths[i];
@@ -329,6 +329,7 @@ export function join(...paths: string[]): string {
   //   path.join('//server', 'share') -> '\\\\server\\share\\')
   let needsReplace = true;
   let slashCount = 0;
+  firstPart = firstPart!;
   if (isPathSeparator(firstPart.charCodeAt(0))) {
     ++slashCount;
     const firstLen = firstPart.length;