Check that modern APIs are used by wmdietl · Pull Request #1342 · eisop/checker-framework

wmdietl · 2025-07-15T23:54:17Z

Apply the "modernizer" plugin to all sources to ensure modern APIs are used.

wmdietl · 2025-07-15T23:55:18Z

@thisisalexandercook Could you please take over this PR and see whether the API changes make sense?
In framework-test, maybe we should restructure this more and use Path instead of File in more places, to avoid converting between them.

…rnizer

Copilot

Pull request overview

Applies the Gradle modernizer plugin across modules and updates several Java sources to prefer java.nio.file/stream APIs over legacy java.io usage.

Changes:

Adds and configures the com.github.andygoossens.modernizer Gradle plugin (including in dev test script).
Replaces many new File(...), string path concatenations, and FileInputStream usages with Paths/Path, Files, and InputStream.
Minor API modernization in tests (e.g., Scanner charset overload, Optional.orElseThrow()).

Reviewed changes

Copilot reviewed 16 out of 17 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
javacutil/src/main/java/org/checkerframework/javacutil/SystemUtil.java	Switches to `Path` construction for `tools.jar`.
framework/src/main/java/org/checkerframework/framework/util/CheckerMain.java	Uses `Paths/Path` resolution and `Files.newInputStream` instead of `FileInputStream`.
framework-test/src/main/java/org/checkerframework/framework/test/diagnostics/JavaDiagnosticReader.java	Uses `Paths` to derive filename from `JavaFileObject`.
framework-test/src/main/java/org/checkerframework/framework/test/TestUtilities.java	Migrates several path/file constructions to `Path`/`resolve`.
framework-test/src/main/java/org/checkerframework/framework/test/TestConfigurationBuilder.java	Creates output dir via `Paths.get(...).toFile()`.
framework-test/src/main/java/org/checkerframework/framework/test/RootedSuite.java	Uses `Path.of(...).toFile()` for test root resolution.
framework-test/src/main/java/org/checkerframework/framework/test/CheckerFrameworkWPIPerDirectoryTest.java	Uses `Scanner(File, Charset)` overload.
framework-test/src/main/java/org/checkerframework/framework/test/CheckerFrameworkRootedTest.java	Uses `Paths.get(...).toFile()` for test root resolution.
framework-test/src/main/java/org/checkerframework/framework/test/CheckerFrameworkPerFileTest.java	Constructs directory paths via `Path.resolve(...).toString()`.
framework-test/src/main/java/org/checkerframework/framework/test/CheckerFrameworkPerDirectoryTest.java	Constructs directory paths via `Path.resolve(...).toString()`.
framework-test/src/main/java/org/checkerframework/framework/test/AinferValidatePerDirectoryTest.java	Replaces `File.exists()` with `Files.exists(Paths.get(...))`.
dataflow/src/main/java/org/checkerframework/dataflow/cfg/visualize/DOTCFGVisualizer.java	Uses `Paths.get(outDir, "methods.txt")` instead of string concatenation.
dataflow/src/main/java/org/checkerframework/dataflow/cfg/visualize/CFGVisualizeOptions.java	Switches to `Path.of(...).toFile()` for input file handling.
checker/src/main/java/org/checkerframework/checker/units/UnitsAnnotatedTypeFactory.java	Uses `Paths.get(...).toFile().exists()` for units dir existence check.
checker/bin-devel/test-misc.sh	Adds `./gradlew modernizer` check.
checker-util/src/test/java/org/checkerframework/checker/optional/util/OptionalUtilTest.java	Uses `Optional.orElseThrow()` instead of `get()`.
build.gradle	Adds and configures the modernizer plugin for all projects.

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Copilot · 2026-02-28T23:49:31Z

            }
        }
-        File toolsJarFile = new File(new File(javaHome, "lib"), "tools.jar");
+        File toolsJarFile = Path.of(javaHome, "lib", "tools.jar").toFile();


Path.of(...) is a Java 11+ API. This change will break compilation when targeting Java 8 (and conflicts with the Gradle modernizer configuration setting javaVersion = 8). Use Paths.get(javaHome, \"lib\", \"tools.jar\") (Java 7+) instead.

Copilot · 2026-02-28T23:49:32Z

+            return Path.of(annotation.value()).toFile();
        }
-        return new File("tests");
+        return Path.of("tests").toFile();


Path.of(...) requires Java 11+. If this project is intended to be compatible with Java 8 (as indicated by modernizer javaVersion = 8), replace these with Paths.get(...).

Copilot · 2026-02-28T23:49:32Z

        }
        String input = args[0];
-        File file = new File(input);
+        File file = Path.of(input).toFile();


Path.of(...) is not available on Java 8. To preserve Java 8 compatibility, use Paths.get(input).toFile() here.

Copilot · 2026-02-28T23:49:32Z


        this.checkerJar = checkerJar;
-        File searchPath = checkerJar.getParentFile();
+        Path searchPath = checkerJar.getParentFile().toPath();


Behavior change: checkerJar.getParentFile() can be null, but new File(parent, child) previously tolerated a null parent (interpreting child as a relative path). The new code will throw NullPointerException when checkerJar has no parent. Consider deriving searchPath from checkerJar.toPath().getParent() and falling back to a sensible default (e.g., current directory) when the parent is null.

Suggested change

Path searchPath = checkerJar.getParentFile().toPath();

Path parent = checkerJar.toPath().getParent();

Path searchPath = (parent != null) ? parent : Paths.get(".");

Copilot · 2026-02-28T23:49:32Z

                extractFileArg(
-                        CHECKER_QUAL_PATH_OPT, new File(searchPath, "checker-qual.jar"), args);
+                        CHECKER_QUAL_PATH_OPT,
+                        searchPath.resolve("checker-qual.jar").toFile(),


Behavior change: checkerJar.getParentFile() can be null, but new File(parent, child) previously tolerated a null parent (interpreting child as a relative path). The new code will throw NullPointerException when checkerJar has no parent. Consider deriving searchPath from checkerJar.toPath().getParent() and falling back to a sensible default (e.g., current directory) when the parent is null.

Copilot · 2026-02-28T23:49:33Z

+                        searchPath.resolve("checker-util.jar").toFile(),
+                        args);

-        this.javacJar = extractFileArg(JAVAC_PATH_OPT, new File(searchPath, "javac.jar"), args);
+        this.javacJar =
+                extractFileArg(JAVAC_PATH_OPT, searchPath.resolve("javac.jar").toFile(), args);


Behavior change: checkerJar.getParentFile() can be null, but new File(parent, child) previously tolerated a null parent (interpreting child as a relative path). The new code will throw NullPointerException when checkerJar has no parent. Consider deriving searchPath from checkerJar.toPath().getParent() and falling back to a sensible default (e.g., current directory) when the parent is null.

Copilot · 2026-02-28T23:49:33Z

    public static List<Object[]> findFilesInParent(File parent, String... fileNames) {
        return CollectionsPlume.mapList(
-                (String fileName) -> new Object[] {new File(parent, fileName)}, fileNames);
+                (String fileName) -> new Object[] {parent.toPath().resolve(fileName)}, fileNames);


This changes the element type from File to Path inside the returned Object[]. Callers (especially JUnit parameterized tests) that expect a File will now fail with a ClassCastException or method signature mismatch. Convert the resolved path back to File (e.g., .toFile()) to preserve the original API behavior.

Suggested change

(String fileName) -> new Object[] {parent.toPath().resolve(fileName)}, fileNames);

(String fileName) ->

new Object[] {parent.toPath().resolve(fileName).toFile()},

fileNames);

Copilot · 2026-02-28T23:49:33Z

        Assert.assertTrue(nonEmptyOpt.isPresent());
        @Present Optional<String> foo = OptionalUtil.castPresent(nonEmptyOpt);
-        Assert.assertEquals(foo.get(), "non-empty");
+        Assert.assertEquals(foo.orElseThrow(), "non-empty");


Assert.assertEquals conventionally uses (expected, actual). Swapping the arguments makes failure messages confusing. Prefer Assert.assertEquals(\"non-empty\", foo.orElseThrow());.

Suggested change

Assert.assertEquals(foo.orElseThrow(), "non-empty");

Assert.assertEquals("non-empty", foo.orElseThrow());

…rnizer

…modernizer

wmdietl · 2026-03-01T20:46:53Z

@thisisalexandercook Should we abandon this PR?

thisisalexandercook · 2026-03-02T20:34:56Z

@thisisalexandercook Should we abandon this PR?

I have let this rot without giving the plugin a good try. I will experiment this week to see how useful it is.

wmdietl added 2 commits July 15, 2025 19:50

Check that modern APIs are used

0365724

Start addressing modernizer comments

20fab0d

wmdietl assigned thisisalexandercook Jul 15, 2025

wmdietl added 2 commits February 28, 2026 18:39

Merge branch 'master' of github.com:eisop/checker-framework into mode…

e591ac4

…rnizer

Update modernizer version

d18a5c2

Copilot AI review requested due to automatic review settings February 28, 2026 23:43

Copilot AI reviewed Feb 28, 2026

View reviewed changes

Copilot started reviewing on behalf of wmdietl February 28, 2026 23:51 View session

wmdietl added 5 commits February 28, 2026 21:02

Merge branch 'master' into modernizer

86498e9

Merge branch 'master' of github.com:eisop/checker-framework into mode…

3d993fa

…rnizer

Skip javadoc

57f7b4a

Merge branch 'modernizer' of github.com:eisop/checker-framework into …

24779e6

…modernizer

Fix order of arguments

bd1ccf1

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Check that modern APIs are used#1342

Check that modern APIs are used#1342
wmdietl wants to merge 9 commits intomasterfrom
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	Path searchPath = checkerJar.getParentFile().toPath();
	Path parent = checkerJar.toPath().getParent();
	Path searchPath = (parent != null) ? parent : Paths.get(".");

	Assert.assertEquals(foo.orElseThrow(), "non-empty");
	Assert.assertEquals("non-empty", foo.orElseThrow());

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