Dry run

docs/reference/cli.md

@@ -1072,6 +1072,11 @@ The `run` command is used to execute a local pipeline script or remote pipeline
 `-disable-jobs-cancellation`
 : Prevent the cancellation of child jobs on execution termination
 
+`-dry`
+: :::{versionadded} 25.10.0
+  :::
+: Print the tasks that will be executed, then exit without executing any tasks. Can be combined with `-resume` to test how much a previous run can be resumed.
+
 `-dsl1`
 : :::{deprecated} 23.09.0-edge
   :::

modules/nextflow/src/main/groovy/nextflow/Session.groovy

@@ -128,6 +128,11 @@ class Session implements ISession {
      */
     boolean resumeMode
 
+    /**
+     * whenever it has been launched as a dry run
+     */
+    boolean dryRun
+
     /**
      * The folder where workflow outputs are stored
      */
@@ -363,11 +368,14 @@ class Session implements ISession {
         }
         log.debug "Session UUID: $uniqueId"
 
+        // -- dry run
+        this.dryRun = config.dryRun
+
         // -- set the run name
         this.runName = config.runName ?: NameGenerator.next()
         log.debug "Run name: $runName"
 
-        // -- dry run
+        // -- stub run
         this.stubRun = config.stubRun
 
         // -- preview

modules/nextflow/src/main/groovy/nextflow/cli/CmdRun.groovy

@@ -97,6 +97,9 @@ class CmdRun extends CmdBase implements HubOptions {
     @Parameter(names=['-resume'], description = 'Execute the script using the cached results, useful to continue executions that was stopped by an error')
     String resume
 
+    @Parameter(names=['-dry'], description = 'Print the tasks that will be executed, then exit without executing any tasks')
+    boolean dryRun
+
     @Parameter(names=['-ps','-pool-size'], description = 'Number of threads in the execution pool', hidden = true)
     Integer poolSize
 

modules/nextflow/src/main/groovy/nextflow/config/ConfigBuilder.groovy

@@ -601,6 +601,11 @@ class ConfigBuilder {
         if( cmdRun.resume )
             config.resume = cmdRun.resume
 
+        // -- sets the dry run option
+        if( cmdRun.dryRun ) {
+            config.dryRun = cmdRun.dryRun
+        }
+
         if( config.isSet('resume') )
             config.resume = normalizeResumeId(config.resume as String)
 

modules/nextflow/src/main/groovy/nextflow/processor/TaskProcessor.groovy

@@ -72,6 +72,7 @@ import nextflow.executor.CachedTaskHandler
 import nextflow.executor.Executor
 import nextflow.executor.StoredTaskHandler
 import nextflow.extension.CH
+import nextflow.extension.ChannelEx
 import nextflow.extension.DataflowHelper
 import nextflow.file.FileHelper
 import nextflow.file.FileHolder
@@ -825,6 +826,12 @@ class TaskProcessor {
                 continue
             }
 
+            if( session.dryRun ) {
+                log.info "[DRY RUN] execute task > ${safeTaskName(task)} [${hash}]"
+                ChannelEx.update(state) { StateObj it -> it.incCompleted() }
+                break
+            }
+
             final lock = lockManager.acquire(hash)
             final workDir = task.getWorkDirFor(hash)
             try {