Add tests checking whether the links haven't changed

.github/workflows/scaladoc.yaml

@@ -52,11 +52,15 @@ jobs:
       - name: Generate testcases documentation
         run: ./project/scripts/sbt scaladoc/generateTestcasesDocumentation
 
-      - name: Generate reference documentation
-        run: ./project/scripts/sbt scaladoc/generateReferenceDocumentation
+      - name: Generate reference documentation and check links stability
+        run: |
+          ./project/scripts/sbt scaladoc/generateReferenceDocumentation
+          ./project/scripts/docsLinksStability ./scaladoc/output/reference ./project/scripts/expected-links/reference-expected-links.txt
 
-      - name: Generate Scala 3 documentation
-        run: ./project/scripts/sbt scaladoc/generateScalaDocumentation
+      - name: Generate Scala 3 documentation and check links stability
+        run: |
+          ./project/scripts/sbt scaladoc/generateScalaDocumentation
+          ./project/scripts/docsLinksStability ./scaladoc/output/scala3 ./project/scripts/expected-links/scala3-expected-links.txt
 
       - name: Generate documentation for example project using dotty-sbt
         run: ./project/scripts/sbt "sbt-test/scripted sbt-dotty/scaladoc"

project/scripts/docsLinksStability

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+set -u
+
+echo "Testing links stability in documentation"
+
+DOCS_DIR=$1 # The location of documentation is passed as a first parameter
+
+EXPECTED_LINKS_FILE=$2 # The location of expected-links.txt is passed as a second parameter
+
+pushd $DOCS_DIR > /dev/null # Go to docs dir but remember previous location
+# We need to go to docs dir to make find return correct relative paths
+find . -type f -name "*.html" | sort | (popd > /dev/null; diff $EXPECTED_LINKS_FILE -;)
+# We list every html file in documentation, then sort it and finally compare to the expected links list.
+# Before running diff we need to popd to return to the previous location because we don't have relative path to the expected links file.
+
+if [ ! $? -eq 0 ]
+then
+  echo "Links changed. If it's intentional, regenerate expected links list by running ./project/scripts/regenerateExpectedLinks $1 $2"
+  exit -1
+else
+  echo "Links OK!"
+  exit 0
+fi

project/scripts/expected-links/reference-expected-links.txt

@@ -0,0 +1,120 @@
+./changed-features/compiler-plugins.html
+./changed-features/eta-expansion-spec.html
+./changed-features/eta-expansion.html
+./changed-features/implicit-conversions-spec.html
+./changed-features/implicit-conversions.html
+./changed-features/implicit-resolution.html
+./changed-features/imports.html
+./changed-features/index.html
+./changed-features/lazy-vals-init.html
+./changed-features/main-functions.html
+./changed-features/match-syntax.html
+./changed-features/numeric-literals.html
+./changed-features/operators.html
+./changed-features/overload-resolution.html
+./changed-features/pattern-bindings.html
+./changed-features/pattern-matching.html
+./changed-features/structural-types-spec.html
+./changed-features/structural-types.html
+./changed-features/type-checking.html
+./changed-features/type-inference.html
+./changed-features/vararg-splices.html
+./changed-features/wildcards.html
+./contextual/by-name-context-parameters.html
+./contextual/context-bounds.html
+./contextual/context-functions-spec.html
+./contextual/context-functions.html
+./contextual/conversions.html
+./contextual/derivation-macro.html
+./contextual/derivation.html
+./contextual/extension-methods.html
+./contextual/given-imports.html
+./contextual/givens.html
+./contextual/index.html
+./contextual/multiversal-equality.html
+./contextual/relationship-implicits.html
+./contextual/right-associative-extension-methods.html
+./contextual/type-classes.html
+./contextual/using-clauses.html
+./docs/reference/other-new-features/named-typeargs.html
+./docsScalaLangResources/scaladoc-assets.html
+./dropped-features/auto-apply.html
+./dropped-features/class-shadowing-spec.html
+./dropped-features/class-shadowing.html
+./dropped-features/delayed-init.html
+./dropped-features/do-while.html
+./dropped-features/early-initializers.html
+./dropped-features/existential-types.html
+./dropped-features/index.html
+./dropped-features/limit22.html
+./dropped-features/macros.html
+./dropped-features/nonlocal-returns.html
+./dropped-features/package-objects.html
+./dropped-features/procedure-syntax.html
+./dropped-features/symlits.html
+./dropped-features/this-qualifier.html
+./dropped-features/type-projection.html
+./dropped-features/weak-conformance-spec.html
+./dropped-features/weak-conformance.html
+./dropped-features/wildcard-init.html
+./dropped-features/xml.html
+./enums/adts.html
+./enums/desugarEnums.html
+./enums/enums.html
+./enums/index.html
+./experimental/canthrow.html
+./experimental/cc.html
+./experimental/erased-defs-spec.html
+./experimental/erased-defs.html
+./experimental/explicit-nulls.html
+./experimental/index.html
+./experimental/named-typeargs-spec.html
+./experimental/named-typeargs.html
+./experimental/numeric-literals.html
+./experimental/overview.html
+./features-classification.html
+./index.html
+./language-versions/binary-compatibility.html
+./language-versions/index.html
+./language-versions/source-compatibility.html
+./metaprogramming/compiletime-ops.html
+./metaprogramming/index.html
+./metaprogramming/inline.html
+./metaprogramming/macros-spec.html
+./metaprogramming/macros.html
+./metaprogramming/reflection.html
+./metaprogramming/staging.html
+./metaprogramming/tasty-inspect.html
+./new-types/dependent-function-types-spec.html
+./new-types/dependent-function-types.html
+./new-types/index.html
+./new-types/intersection-types-spec.html
+./new-types/intersection-types.html
+./new-types/match-types.html
+./new-types/polymorphic-function-types.html
+./new-types/type-lambdas-spec.html
+./new-types/type-lambdas.html
+./new-types/union-types-spec.html
+./new-types/union-types.html
+./other-new-features/control-syntax.html
+./other-new-features/creator-applications.html
+./other-new-features/experimental-defs.html
+./other-new-features/export.html
+./other-new-features/indentation.html
+./other-new-features/index.html
+./other-new-features/kind-polymorphism.html
+./other-new-features/matchable.html
+./other-new-features/opaques-details.html
+./other-new-features/opaques.html
+./other-new-features/open-classes.html
+./other-new-features/parameter-untupling-spec.html
+./other-new-features/parameter-untupling.html
+./other-new-features/safe-initialization.html
+./other-new-features/targetName.html
+./other-new-features/threadUnsafe-annotation.html
+./other-new-features/trait-parameters.html
+./other-new-features/transparent-traits.html
+./other-new-features/type-test.html
+./overview.html
+./soft-modifier.html
+./syntax.html