Add example of false positive with re-export involving index and * (#269

)

Improve support of re-exports involving *. Improve output for such exports.

* Add example of false positive with re-export involving index and *
* Avoid false positives when a export * is partly imported at a higher level
* Add explicit null use
* Add more tests and nicer format if unused involves export *
* Add version bump to help when releasing
* 9.0.4

CHANGELOG.md

@@ -1,3 +1,10 @@
+## [9.0.4] - 12 Feb 2023
+
+### Changed
+
+- Improve handling of transitive imports like 'a -> b -> c' especially where 'export *' is used - #216
+- Improve output format when the unused item involves an 'export *'.
+
 ## [9.0.3] - 5 Feb 2023
 
 ### Changed

example/import-and-re-export-2/execute.sh

@@ -0,0 +1 @@
+../../bin/ts-unused-exports ./tsconfig.json

example/import-and-re-export-2/src/a/index.ts

@@ -0,0 +1,2 @@
+export const A = 1;
+export const A_2 = 1;

example/import-and-re-export-2/src/b.ts

@@ -0,0 +1,2 @@
+export * as fromA from './a';
+export const B_unused = 1;

example/import-and-re-export-2/src/c.ts

@@ -0,0 +1,2 @@
+import { fromA } from './b';
+export const C_unused = 1;

example/import-and-re-export-2/tsconfig.json

@@ -0,0 +1,3 @@
+{
+    "include": ["src"]
+}

example/import-and-re-export/execute.sh

@@ -0,0 +1 @@
+../../bin/ts-unused-exports ./tsconfig.json

example/import-and-re-export/src/a/a/a.ts

@@ -0,0 +1,2 @@
+export const a = 0
+export const unusedInInnerIndex = 0

example/import-and-re-export/src/a/a/a_unused.ts

@@ -0,0 +1 @@
+export const unusedInA = 0

example/import-and-re-export/src/a/a/index.ts

@@ -0,0 +1 @@
+export * from './a'

example/import-and-re-export/src/a/index.ts

@@ -0,0 +1,2 @@
+export * from './a'
+

example/import-and-re-export/src/index.ts

@@ -0,0 +1,3 @@
+import { a } from './a'
+
+export const unusedInTopIndex = 0

example/import-and-re-export/tsconfig.json

@@ -0,0 +1,3 @@
+{
+    "include": ["src"]
+}

features/export-statements-star.feature

@@ -12,6 +12,148 @@ Scenario: export * from ./a/a.ts
   When analyzing "tsconfig.json"
   Then the result is { "b.ts": ["A_unused"] }
 
+Scenario: export * from ./a/a/a.ts
+  Given file "a/a/a.ts" is
+    """
+    export const A = 1;
+    export const A_innermost_unused = 1;
+    """
+  And file "a/a/index.ts" is
+    """
+    export * from "./a";
+    """
+  And file "a/a.ts" is export * from './a';
+  And file "a/index.ts" is
+    """
+    export * from "./a";
+    export const A_unused = 1;
+    """
+  And file "c.ts" is import { A } from './a';
+
+  When analyzing "tsconfig.json"
+  # note A_innermost_unused is not detected - that would require parsing for all usages of the namespace
+  Then the result is { "a/index.ts": ["A_unused"] }
+
+Scenario: export * from ./a1/a2/a.ts
+  Given file "a1/a2/a.ts" is
+    """
+    export const A = 1;
+    export const A_innermost_unused = 1;
+    """
+  And file "a1/a2/index.ts" is
+    """
+    export * from "./a";
+    """
+  And file "a1/a.ts" is export * from './a2';
+  And file "a1/index.ts" is
+    """
+    export * from "./a";
+    export const A_unused = 1;
+    """
+  And file "c.ts" is import { A } from './a1';
+
+  When analyzing "tsconfig.json"
+  # note A_innermost_unused is not detected - that would require parsing for all usages of the namespace
+  Then the result is { "a1/index.ts": ["A_unused"] }
+
+Scenario: export * from ./a1/a2/a.ts - import skipping the mid-level - import from innermost index
+  Given file "a1/a2/a.ts" is
+    """
+    export const A = 1;
+    export const A_innermost_unused = 1;
+    """
+  And file "a1/a2/index.ts" is
+    """
+    export * from "./a";
+    """
+  # note this IS flagged as unused
+  And file "a1/a.ts" is export * from './a2';
+  And file "a1/index.ts" is
+    """
+    // skips the mid-level file a1/a.ts
+    export * from "./a1/a2";
+    export const A_unused = 1;
+    """
+  And file "c.ts" is import { A } from './a1';
+
+  When analyzing "tsconfig.json"
+  # note A_innermost_unused is NOT detected
+  Then the result is { "a1/a_ts":["* -> /a1/a2/a"], "a1/index.ts": ["A_unused"] }
+
+Scenario: export * from ./a1/a2/a.ts - import skipping the mid-level - import from innermost a.ts
+  Given file "a1/a2/a.ts" is
+    """
+    export const A = 1;
+    export const A_innermost_unused = 1;
+    """
+  # TODO this could be flagged as unused
+  And file "a1/a2/index.ts" is
+    """
+    export * from "./a";
+    """
+  # TODO this could be flagged as unused
+  And file "a1/a.ts" is export * from './a';
+  And file "a1/index.ts" is
+    """
+    // skips the mid-level - imports directly from a1/a2/a.ts NOT the index, so not from an export *
+    export * from "./a1/a2/a";
+    export const A_unused = 1;
+    """
+  And file "c.ts" is import { A } from './a1';
+
+  When analyzing "tsconfig.json"
+  # note A_innermost_unused is NOT detected
+  # TODO review - A is flagged via "a1/a2/index_ts":["A"...] - which is strictly correct, although could be annoying
+  Then the result is { "a1/index.ts": ["A_unused"],"a1/a2/index_ts":["A","A_innermost_unused"] }
+
+Scenario: export * from ./a/a/a.ts - import skipping the mid-level
+  Given file "a/a/a.ts" is
+    """
+    export const A = 1;
+    export const A_innermost_unused = 1;
+    """
+  And file "a/a/index.ts" is
+    # TODO this could be flagged as unused
+    """
+    export * from "./a";
+    """
+  And file "a/a.ts" is export * from './a';
+  And file "a/index.ts" is
+    """
+    // skips the mid-level
+    export * from "./a/a";
+    export const A_unused = 1;
+    """
+  And file "c.ts" is import { A } from './a';
+
+  When analyzing "tsconfig.json"
+  # note A_innermost_unused IS detected
+  Then the result is { "a/index.ts": ["A_unused", "A_innermost_unused"] }
+
+Scenario: export * from ./a/a/a.ts - import skipping the mid-level
+  Given file "a/a/a.ts" is
+    """
+    export const A = 1;
+    export const A_innermost_unused = 1;
+    """
+  And file "a/a/index.ts" is
+    """
+    export * from "./a";
+    """
+  # TODO this could be flagged as unused
+  And file "a/a.ts" is export * from './a';
+  And file "a/index.ts" is
+    """
+    // skips the mid-level - imports directly from a/a/a.ts NOT the index, so not from an export *
+    export * from "./a/a/a";
+    export const A_unused = 1;
+    """
+  And file "c.ts" is import { A } from './a';
+
+  When analyzing "tsconfig.json"
+  # note A_innermost_unused is NOT detected
+  Then the result is { "a/index.ts": ["A_unused"] }
+
 Scenario: export * from ./a
   Given file "a/index.ts" is
     """
@@ -34,8 +176,8 @@ Scenario: export * as fromA from ./a/a.ts
   And file "c.ts" is import { fromA } from './b';
 
   When analyzing "tsconfig.json"
+  # note A_unused is not detected - that would require parsing for all usages of the namespace
   Then the result is { }
-# note A_unused is not detected - that would require parsing for all usages of the namespace
 
 Scenario: export * as fromA from ./a/a.ts
   Given file "a/a.ts" is

ispec/run.sh

@@ -83,6 +83,14 @@ pushd ../example/path-alias-and-sub-folders-import-from-index
 run_itest
 popd
 
+pushd ../example/import-and-re-export
+run_itest
+popd
+
+pushd ../example/import-and-re-export-2
+run_itest
+popd
+
 pushd ../example/with-js
 run_itest
 popd

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ts-unused-exports",
-  "version": "9.0.3",
+  "version": "9.0.4",
   "description": "ts-unused-exports finds unused exported symbols in your Typescript project",
   "main": "lib/app.js",
   "repository": {
@@ -21,6 +21,7 @@
   },
   "homepage": "https://github.com/pzavolinsky/ts-unused-exports",
   "scripts": {
+    "bump": "npm version patch",
     "build": "tsc",
     "exec": "bin/ts-unused-exports",
     "lint:fix": "./node_modules/.bin/eslint --ext .ts src --fix",

src/analyzer.ts

@@ -1,6 +1,7 @@
 import {
   Analysis,
   ExtraCommandLineOptions,
+  ExtraOptionsForPresentation,
   File,
   LocationInFile,
 } from './types';
@@ -25,6 +26,8 @@ interface FileExports {
 interface ExportItem {
   exports: FileExports;
   path: string;
+  // Was the file imported at least once. If so, then can mark any export * as used (handles transitive export(import) like a -> b -> c).
+  fileWasImported: boolean;
 }
 
 interface ExportMap {
@@ -61,7 +64,7 @@ const getFileExports = (file: File): ExportItem => {
     }
   });
 
-  return { exports, path: file.fullPath };
+  return { exports, path: file.fullPath, fileWasImported: false };
 };
 
 const getExportMap = (files: File[]): ExportMap => {
@@ -74,7 +77,10 @@ const getExportMap = (files: File[]): ExportMap => {
 
 const processImports = (file: File, exportMap: ExportMap): void => {
   Object.keys(file.imports).forEach((key) => {
-    let ex = exportMap[removeFileExtensionToAllowForJs(key)]?.exports;
+    const importedFileExports =
+      exportMap[removeFileExtensionToAllowForJs(key)] || null;
+
+    let ex = importedFileExports?.exports || null;
 
     // Handle imports from an index file
     if (!ex) {
@@ -121,9 +127,15 @@ const processImports = (file: File, exportMap: ExportMap): void => {
           },
         };
       }
+
+      // DEV DEBUG - console.log(`Marking as used: ${imp} in ${file.path}`);
       ex[imp].usageCount++;
     };
 
+    if (!!importedFileExports) {
+      importedFileExports.fileWasImported = true;
+    }
+
     file.imports[key].forEach((imp) => {
       imp === '*' ? Object.keys(ex).forEach(addUsage) : addUsage(imp);
     });
@@ -164,6 +176,12 @@ const expandExportFromStarOrStarAsForFile = (
             // Mark the items as imported, for the imported file:
             const importedFileExports = exportMap[removeExportStarPrefix(ex)];
             if (importedFileExports) {
+              // DEV DEBUG
+              /* console.log(
+                `Marking as used: ${key} in ${removeExportStarPrefix(ex)}`,
+              );
+              console.dir(Object.keys(exportMap));*/
+              importedFileExports.fileWasImported = true;
               importedFileExports.exports[key].usageCount++;
             }
           });
@@ -233,9 +251,24 @@ const areEqual = (files1: string[], files2: string[]): boolean => {
   return files1.every((f) => files2.includes(f));
 };
 
+const makeExportStarRelativeForPresentation = (
+  baseUrl: string | undefined,
+  filePath: string,
+): string => {
+  if (!filePath.startsWith('*')) {
+    return filePath;
+  }
+
+  const filePathNoStar = removeExportStarPrefix(filePath);
+  if (!!baseUrl && filePathNoStar.startsWith(baseUrl)) {
+    return `* -> ${filePathNoStar.substring(baseUrl.length)}`;
+  }
+  return filePath;
+};
+
 export default (
   files: File[],
-  extraOptions?: ExtraCommandLineOptions,
+  extraOptions?: ExtraCommandLineOptions & ExtraOptionsForPresentation,
 ): Analysis => {
   const filteredFiles = filterFiles(files, extraOptions);
 
@@ -252,9 +285,15 @@ export default (
 
     if (shouldPathBeExcludedFromResults(path, extraOptions)) return;
 
-    const unusedExports = Object.keys(exports).filter(
-      (k) => exports[k].usageCount === 0,
-    );
+    const unusedExports = Object.keys(exports).filter((k) => {
+      // If the file was imported at least once, then do NOT consider any of its 'export (import) *' as unused.
+      // This avoids false positives with transitive import/exports like a -> b -> c.
+      if (expItem.fileWasImported && k.startsWith('*')) {
+        return false;
+      }
+
+      return exports[k].usageCount === 0;
+    });
 
     if (unusedExports.length === 0) {
       return;
@@ -265,7 +304,10 @@ export default (
     analysis[path] = [];
     unusedExports.forEach((e) => {
       analysis[path].push({
-        exportName: e,
+        exportName: makeExportStarRelativeForPresentation(
+          extraOptions?.baseUrl,
+          e,
+        ),
         location: exports[e].location,
       });
     });

src/app.ts

@@ -60,5 +60,9 @@ export default (tsconfigPath: string, files?: string[]): Analysis => {
   const args = extractOptionsFromFiles(files);
   const tsConfig = loadTsConfig(tsconfigPath, args.tsFiles);
 
-  return analyze(parseFiles(tsConfig, args.options), args.options);
+  const options = {
+    ...args.options,
+    baseUrl: tsConfig.baseUrl,
+  };
+  return analyze(parseFiles(tsConfig, args.options), options);
 };

src/types.ts

@@ -57,3 +57,7 @@ export interface ExtraCommandLineOptions {
   silent?: boolean;
   findCompletelyUnusedFiles?: boolean;
 }
+
+export interface ExtraOptionsForPresentation {
+  baseUrl?: string;
+}