--json and --json-file CLI args add to lfc

build.gradle

@@ -42,8 +42,8 @@ subprojects {
         implementation group: 'com.google.inject', name: 'guice', version: guiceVersion
         // https://picocli.info/
         implementation group: 'info.picocli', name: 'picocli', version: picocliVersion
-    }
-    dependencies {
+        // https://mvnrepository.com/artifact/com.google.code.gson/gson
+        implementation group: 'com.google.code.gson', name: 'gson', version: gsonVersion
         implementation group: 'org.jetbrains.kotlin', name: 'kotlin-stdlib', version: kotlinVersion
         implementation group: 'org.jetbrains.kotlin', name: 'kotlin-reflect', version: kotlinVersion
     }

gradle.properties

@@ -3,9 +3,9 @@ group=org.lflang
 version=0.4.1-SNAPSHOT
 
 [versions]
-picocliVersion=4.7.0
 googleJavaFormatVersion=1.15.0
 guiceVersion=5.1.0
+gsonVersion=2.10.1
 jacocoVersion=0.8.7
 jupiterVersion=5.8.2
 jUnitPlatformVersion=1.8.2
@@ -15,6 +15,7 @@ kotlinVersion=1.6.20
 lsp4jVersion=0.14.0
 mwe2LaunchVersion=2.12.2
 openTest4jVersion=1.2.0
+picocliVersion=4.7.0
 resourcesVersion=3.16.0
 shadowJarVersion=7.1.2
 spotlessVersion=6.11.0

org.lflang.tests/src/org/lflang/tests/cli/LfcCliTest.java

@@ -62,6 +62,29 @@ public class LfcCliTest {
         }
         """;
 
+    static final String JSON_STRING = """
+        {
+            "src": "src/File.lf",
+            "out": "src",
+            "properties": {
+                "build-type": "Release",
+                "clean": true,
+                "target-compiler": "gcc",
+                "external-runtime-path": "src",
+                "federated": true,
+                "logging": "info",
+                "lint": true,
+                "no-compile": true,
+                "quiet": true,
+                "rti": "path/to/rti",
+                "runtime-version": "rs",
+                "scheduler": "GEDF_NP",
+                "threading": false,
+                "workers": "1"
+            }
+        }
+        """;
+
     @Test
     public void testHelpArg() {
         lfcTester.run("--help", "--version")
@@ -72,6 +95,30 @@ public void testHelpArg() {
             });
     }
 
+    @Test
+    public void testMutuallyExclusiveCliArgs() {
+        lfcTester.run("File.lf", "--json", JSON_STRING)
+            .verify(result -> {
+                result.checkStdErr(containsString(
+                            "are mutually exclusive (specify only one)"));
+                result.checkFailed();
+            });
+
+        lfcTester.run("File.lf", "--json-file", "test.json")
+            .verify(result -> {
+                result.checkStdErr(containsString(
+                            "are mutually exclusive (specify only one)"));
+                result.checkFailed();
+            });
+
+        lfcTester.run("--json", JSON_STRING, "--json-file", "test.json")
+            .verify(result -> {
+                result.checkStdErr(containsString(
+                            "are mutually exclusive (specify only one)"));
+                result.checkFailed();
+            });
+    }
+
     @Test
     public void testVersion() {
         lfcTester.run("--version")
@@ -163,6 +210,31 @@ public void testGenInSrcDir(@TempDir Path tempDir) throws IOException {
             });
     }
 
+    // Helper method for comparing argument values in tests testGeneratorArgs,
+    // testGeneratorArgsJsonString and testGeneratorArgsJsonFile.
+    public void verifyGeneratorArgs(Path tempDir, String[] args) {
+        LfcOneShotTestFixture fixture = new LfcOneShotTestFixture();
+
+        fixture.run(tempDir, args)
+            .verify(result -> {
+                // Don't validate execution because args are dummy args.
+                Properties properties = fixture.lfc.getGeneratorArgs();
+                assertEquals(properties.getProperty(BuildParm.BUILD_TYPE.getKey()), "Release");
+                assertEquals(properties.getProperty(BuildParm.CLEAN.getKey()), "true");
+                assertEquals(properties.getProperty(BuildParm.TARGET_COMPILER.getKey()), "gcc");
+                assertEquals(properties.getProperty(BuildParm.EXTERNAL_RUNTIME_PATH.getKey()), "src");
+                assertEquals(properties.getProperty(BuildParm.LOGGING.getKey()), "info");
+                assertEquals(properties.getProperty(BuildParm.LINT.getKey()), "true");
+                assertEquals(properties.getProperty(BuildParm.NO_COMPILE.getKey()), "true");
+                assertEquals(properties.getProperty(BuildParm.QUIET.getKey()), "true");
+                assertEquals(properties.getProperty(BuildParm.RTI.getKey()), "path/to/rti");
+                assertEquals(properties.getProperty(BuildParm.RUNTIME_VERSION.getKey()), "rs");
+                assertEquals(properties.getProperty(BuildParm.SCHEDULER.getKey()), "GEDF_NP");
+                assertEquals(properties.getProperty(BuildParm.THREADING.getKey()), "false");
+                assertEquals(properties.getProperty(BuildParm.WORKERS.getKey()), "1");
+            });
+    }
+
     @Test
     public void testGeneratorArgs(@TempDir Path tempDir)
             throws IOException {
@@ -188,26 +260,30 @@ public void testGeneratorArgs(@TempDir Path tempDir)
             "--threading", "false",
             "--workers", "1",
         };
-        LfcOneShotTestFixture fixture = new LfcOneShotTestFixture();
+        verifyGeneratorArgs(tempDir, args);
+    }
 
-        fixture.run(tempDir, args)
-            .verify(result -> {
-                // Don't validate execution because args are dummy args.
-                Properties properties = fixture.lfc.getGeneratorArgs();
-                assertEquals(properties.getProperty(BuildParm.BUILD_TYPE.getKey()), "Release");
-                assertEquals(properties.getProperty(BuildParm.CLEAN.getKey()), "true");
-                assertEquals(properties.getProperty(BuildParm.TARGET_COMPILER.getKey()), "gcc");
-                assertEquals(properties.getProperty(BuildParm.EXTERNAL_RUNTIME_PATH.getKey()), "src");
-                assertEquals(properties.getProperty(BuildParm.LOGGING.getKey()), "info");
-                assertEquals(properties.getProperty(BuildParm.LINT.getKey()), "true");
-                assertEquals(properties.getProperty(BuildParm.NO_COMPILE.getKey()), "true");
-                assertEquals(properties.getProperty(BuildParm.QUIET.getKey()), "true");
-                assertEquals(properties.getProperty(BuildParm.RTI.getKey()), "path/to/rti");
-                assertEquals(properties.getProperty(BuildParm.RUNTIME_VERSION.getKey()), "rs");
-                assertEquals(properties.getProperty(BuildParm.SCHEDULER.getKey()), "GEDF_NP");
-                assertEquals(properties.getProperty(BuildParm.THREADING.getKey()), "false");
-                assertEquals(properties.getProperty(BuildParm.WORKERS.getKey()), "1");
-            });
+    @Test
+    public void testGeneratorArgsJsonString(@TempDir Path tempDir)
+            throws IOException {
+        TempDirBuilder dir = dirBuilder(tempDir);
+        dir.file("src/File.lf", LF_PYTHON_FILE);
+        dir.mkdirs("path//to/rti");
+
+        String[] args = {"--json", JSON_STRING};
+        verifyGeneratorArgs(tempDir, args);
+    }
+
+    @Test
+    public void testGeneratorArgsJsonFile(@TempDir Path tempDir)
+            throws IOException {
+        TempDirBuilder dir = dirBuilder(tempDir);
+        dir.file("src/File.lf", LF_PYTHON_FILE);
+        dir.file("src/test.json", JSON_STRING);
+        dir.mkdirs("path//to/rti");
+
+        String[] args = {"--json-file", "src/test.json"};
+        verifyGeneratorArgs(tempDir, args);
     }
 
     static class LfcTestFixture extends CliToolTestFixture {

org.lflang/src/org/lflang/cli/CliBase.java

@@ -4,12 +4,22 @@
 import java.io.PrintWriter;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map.Entry;
+import java.util.Properties;
+import java.util.Set;
 import java.util.stream.Collectors;
 
 import picocli.CommandLine;
+import picocli.CommandLine.ArgGroup;
+import picocli.CommandLine.Command;
+import picocli.CommandLine.Model.CommandSpec;
 import picocli.CommandLine.Option;
 import picocli.CommandLine.Parameters;
+import picocli.CommandLine.Spec;
 
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.resource.Resource;
@@ -23,6 +33,10 @@
 import org.lflang.LFRuntimeModule;
 import org.lflang.LFStandaloneSetup;
 import org.lflang.util.FileUtil;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import com.google.gson.JsonParseException;
 import com.google.inject.Inject;
 import com.google.inject.Injector;
 import com.google.inject.Provider;
@@ -36,22 +50,42 @@
  * @author Atharva Patil
  */
 public abstract class CliBase implements Runnable {
+    /**
+     * Models a command specification, including the options, positional
+     * parameters and subcommands supported by the command.
+     */
+    @Spec CommandSpec spec;
 
     /**
      * Options and parameters present in both Lfc and Lff.
      */
-    @Parameters(
-        arity = "1..",
-        paramLabel = "FILES",
-        description = "Paths of the files to run Lingua Franca programs on.")
-    protected List<Path> files;
+    static class MutuallyExclusive {
+         @Parameters(
+         arity = "1..",
+         paramLabel = "FILES",
+         description = "Paths of the files to run Lingua Franca programs on.")
+             protected List<Path> files;
+
+         @Option(
+         names="--json",
+         description="JSON object containing CLI arguments.")
+             private String jsonString;
+
+         @Option(
+         names="--json-file",
+         description="JSON file containing CLI arguments.")
+             private Path jsonFile;
+     }
 
-    @Option(
-        names = {"-o", "--output-path"},
-        defaultValue = "",
-        fallbackValue = "",
-        description = "Specify the root output directory.")
-    private Path outputPath;
+     @ArgGroup(exclusive = true, multiplicity = "1")
+     MutuallyExclusive topLevelArg;
+
+     @Option(
+     names = {"-o", "--output-path"},
+     defaultValue = "",
+     fallbackValue = "",
+     description = "Specify the root output directory.")
+         private Path outputPath;
 
     /**
      * Used to collect all errors that happen during validation/generation.
@@ -111,9 +145,39 @@ public void doExecute(Io io, String[] args) {
     /**
      * The entrypoint of Picocli applications - the first method called when 
      * CliBase, which implements the Runnable interface, is instantiated.
-     * Lfc and Lff have their own specific implementations for this method.
      */ 
-    public abstract void run();
+    public void run() {
+        // If args are given in a json file, store its contents in jsonString.
+        if (topLevelArg.jsonFile != null) {
+            try {
+                topLevelArg.jsonString = new String(Files.readAllBytes(
+                        io.getWd().resolve(topLevelArg.jsonFile)));
+            } catch (IOException e) {
+                reporter.printFatalErrorAndExit(
+                        "No such file: " + topLevelArg.jsonFile);
+            }
+        }
+        // If args are given in a json string, (1) unpack them into an args
+        // array, and (2) call cmd.execute on them, which assigns them to their
+        // correct instance variables, then (3) recurses into run().
+        if (topLevelArg.jsonString != null) {
+            // Unpack args from json string.
+            String[] args = jsonStringToArgs(topLevelArg.jsonString);
+            // Execute application on unpacked args.
+            CommandLine cmd = spec.commandLine();
+            int exitCode = cmd.execute(args);
+            io.callSystemExit(exitCode);
+        // If args are already unpacked, invoke tool-specific logic.
+        } else {
+            runTool();
+        }
+    }
+
+    /*
+     * The entrypoint of tool-specific logic.
+     * Lfc and Lff have their own specific implementations for this method.
+     */
+    public abstract void runTool();
 
     public static Injector getInjector(String toolName, Io io) {
         final ReportingBackend reporter 
@@ -139,7 +203,7 @@ protected Path toAbsolutePath(Path other) {
      * @return Validated input paths.
      */
     protected List<Path> getInputPaths() {
-        List<Path> paths = files.stream()
+        List<Path> paths = topLevelArg.files.stream()
             .map(io.getWd()::resolve)
             .collect(Collectors.toList());
 
@@ -252,4 +316,54 @@ public Resource getResource(Path path) {
         }
     }
 
+    private String[] jsonStringToArgs(String jsonString) {
+        ArrayList<String> argsList = new ArrayList<>();
+        JsonObject jsonObject = new JsonObject();
+
+        // Parse JSON string and get top-level JSON object.
+        try {
+            jsonObject = JsonParser.parseString(jsonString).getAsJsonObject();
+        } catch (JsonParseException e) {
+            reporter.printFatalErrorAndExit(
+                    "Invalid JSON string:\n" + jsonString);
+        }
+        // Append input paths.
+        JsonElement src = jsonObject.get("src");
+        if (src == null) {
+            reporter.printFatalErrorAndExit(
+                    "JSON Parse Exception: field \"src\" not found.");
+        }
+        argsList.add(src.getAsString());
+        // Append output path if given.
+        JsonElement out = jsonObject.get("out");
+        if (out != null) {
+            argsList.add("--output-path");
+            argsList.add(out.getAsString());
+        }
+
+        // If there are no other properties, return args array.
+        JsonElement properties = jsonObject.get("properties");
+        if (properties != null) {
+            // Get the remaining properties.
+            Set<Entry<String, JsonElement>> entrySet = properties
+                .getAsJsonObject()
+                .entrySet();
+            // Append the remaining properties to the args array.
+            for(Entry<String,JsonElement> entry : entrySet) {
+                String property = entry.getKey();
+                String value = entry.getValue().getAsString();
+
+                // Append option.
+                argsList.add("--" + property);
+                // Append argument for non-boolean options.
+                if (value != "true" || property == "threading") {
+                    argsList.add(value);
+                }
+            }
+        }
+
+        // Return as String[].
+        String[] args = argsList.toArray(new String[argsList.size()]);
+        return args;
+    }
 }

org.lflang/src/org/lflang/cli/Lfc.java

@@ -156,7 +156,7 @@ public static void main(Io io, final String... args) {
      * Load the resource, validate it, and, invoke the code generator.
      */
     @Override
-    public void run() {
+    public void runTool() {
         List<Path> paths = getInputPaths();
         final Path outputRoot = getOutputRoot();
         // Hard code the props based on the options we want.

org.lflang/src/org/lflang/cli/Lff.java

@@ -88,7 +88,7 @@ public static void main(Io io, final String... args) {
      * Validates all paths and invokes the formatter on the input paths.
      */
     @Override
-    public void run() {
+    public void runTool() {
         List<Path> paths = getInputPaths();
         final Path outputRoot = getOutputRoot();