recipesFound null in upgrade-asciidoc.ftl:46 breaks HTML report generation

[timtebeek]

Describe the bug
Template error generating HTML report.

freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> recipesFound  [in template "upgrade-asciidoc.ftl" at line 46, column 6]

To Reproduce
Steps to reproduce the behavior:

1. checkout spring petclinic on spring boot 2.4

#!/bin/bash
set -e
source "$HOME/.sdkman/bin/sdkman-init.sh"

project='spring-petclinic-sbm'

wget --no-clobber https://github.com/spring-projects-experimental/spring-boot-migrator/releases/download/0.11.0/spring-boot-migrator.jar

git clone [email protected]:spring-projects/spring-petclinic.git $project
cd $project
#git reset --hard
#git clean -f
git checkout 09e07869ac8cea1d08bd62802d5e0dad97827b87 # commit on 2.4.x
cd -

sdk use java 11.0.15-tem
java -jar spring-boot-migrator.jar

3. scan spring-petclinic-sbm
4. apply boot-2.4-2.5-dependency-version-update
5. apply boot-2.4-2.5-sql-init-properties
6. apply boot-2.4-2.5-upgrade-report

Expected behavior
A HTML report, possibly with all steps resolved

Stacktrace

spring-petclinic-sbm:> apply boot-2.4-2.5-upgrade-report
Applying recipe 'boot-2.4-2.5-upgrade-report'
..   Create Upgrade Report for a Spring Boot 2.4 Application16:42:24.213 [main] ERROR freemarker.runtime - Error executing FreeMarker template
freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> recipesFound  [in template "upgrade-asciidoc.ftl" at line 46, column 6]
----
Tip: If the failing expression is known to legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??
----
----
FTL stack trace ("~" means nesting-related):
	- Failed at: #if recipesFound  [in template "upgrade-asciidoc.ftl" at line 46, column 1]
----
	at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:134)
	at freemarker.core.UnexpectedTypeException.newDescriptionBuilder(UnexpectedTypeException.java:85)
	at freemarker.core.UnexpectedTypeException.<init>(UnexpectedTypeException.java:48)
	at freemarker.core.NonBooleanException.<init>(NonBooleanException.java:47)
	at freemarker.core.Expression.modelToBoolean(Expression.java:195)
	at freemarker.core.Expression.evalToBoolean(Expression.java:178)
	at freemarker.core.Expression.evalToBoolean(Expression.java:163)
	at freemarker.core.ConditionalBlock.accept(ConditionalBlock.java:48)
	at freemarker.core.Environment.visit(Environment.java:347)
	at freemarker.core.Environment.visit(Environment.java:353)
	at freemarker.core.Environment.process(Environment.java:326)
	at freemarker.template.Template.process(Template.java:383)
	at org.springframework.sbm.boot.upgrade_24_25.actions.Boot_24_25_UpgradeReportAction.renderMarkdown(Boot_24_25_UpgradeReportAction.java:80)
	at org.springframework.sbm.boot.upgrade_24_25.actions.Boot_24_25_UpgradeReportAction.apply(Boot_24_25_UpgradeReportAction.java:69)
	at org.springframework.sbm.engine.recipe.Action.applyWithStatusEvent(Action.java:37)
	at org.springframework.sbm.engine.recipe.Recipe.lambda$apply$2(Recipe.java:97)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1655)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
	at org.springframework.sbm.engine.recipe.Recipe.apply(Recipe.java:97)
	at org.springframework.sbm.engine.commands.ApplyCommand.execute(ApplyCommand.java:70)
	at org.springframework.sbm.shell.ApplyShellCommand.apply(ApplyShellCommand.java:54)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:282)
	at org.springframework.shell.Shell.evaluate(Shell.java:180)
	at org.springframework.shell.Shell.run(Shell.java:142)
	at org.springframework.shell.jline.InteractiveShellApplicationRunner.run(InteractiveShellApplicationRunner.java:84)
	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:803)
	at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:793)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:346)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1365)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1354)
	at org.springframework.sbm.SpringShellApplication.main(SpringShellApplication.java:27)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:49)
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:108)
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
	at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88)
Action [org.springframework.sbm.boot.upgrade_24_25.actions.Boot_24_25_UpgradeReportAction] with description 'Create Upgrade Report for a Spring Boot 2.4 Application' failed: freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> recipesFound  [in template "upgrade-asciidoc.ftl" at line 46, column 6]
----
Tip: If the failing expression is known to legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??
----
----
FTL stack trace ("~" means nesting-related):
	- Failed at: #if recipesFound  [in template "upgrade-asciidoc.ftl" at line 46, column 1]
----
Details of the error have been omitted. You can use the stacktrace command to print the full stacktrace.

Desktop (please complete the following information):

• OS: Ubuntu 20.04
• Version 11

[timtebeek]

Looking at this answer it might be that this line needs to include two question marks.

-<#if recipesFound>
+<#if recipesFound??>

Although I've never worked with freemarker templates, so there might be a better/other way.

[fabapp2]

Thanks a lot @timtebeek for reporting and solving it!