tests: fix free /review URL test drift via a review_url output

.github/workflows/test-breaking.yaml

@@ -276,105 +276,66 @@ jobs:
   breaking_free_review_url_preserves_https_base:
     runs-on: ubuntu-latest
     name: Test breaking free review URL keeps the https:// scheme on URL-style base
-    # Regression test for the bug class fixed in pr-comment (#120): the naive
-    # base_path=$(echo "$base" | sed 's/.*://') strips "https:" from a
-    # URL-shaped base and leaves a broken "//raw.github..." in the free
-    # /review link, which the page renders as a misleading access-denied
-    # screen. The strip_ref_prefix helper passes URLs through unchanged.
+    # Regression test for the bug fixed in pr-comment (#120): a URL-shaped base
+    # must survive intact in the review URL's base_file, not be mangled to
+    # "//raw.github..." by the git-ref-prefix strip. Runs the real action in its
+    # Alpine container (the production platform) and asserts on the review_url
+    # output. openapi-test1 -> openapi-test3 has breaking changes, so the notice
+    # (and review_url) fire.
     steps:
       - uses: actions/checkout@v6
-      - name: Stub oasdiff to report a change so the notice fires
+      - uses: ./breaking
+        id: brk
+        with:
+          base: 'https://raw.githubusercontent.com/oasdiff/oasdiff/main/data/openapi-test1.yaml'
+          revision: 'https://raw.githubusercontent.com/oasdiff/oasdiff/main/data/openapi-test3.yaml'
+      - name: Assert the full https:// URL is preserved in base_file
+        env:
+          REVIEW_URL: ${{ steps.brk.outputs.review_url }}
         run: |
           set -euo pipefail
-          mkdir -p /tmp/stub
-          cat > /tmp/stub/oasdiff <<'STUB'
-          #!/bin/sh
-          echo '1 breaking change(s)'
-          STUB
-          chmod +x /tmp/stub/oasdiff
-
-          mkdir -p /tmp/run
-          export GITHUB_REPOSITORY=oasdiff-test/test
-          export GITHUB_SHA=deadbeef
-          export GITHUB_BASE_REF=main
-          export GITHUB_OUTPUT=/tmp/run/github-output
-          export GITHUB_STEP_SUMMARY=/tmp/run/step-summary
-          cat > /tmp/run/event.json <<EVT
-          {"pull_request":{"head":{"sha":"deadbeef"},"base":{"sha":"baadcafe"}}}
-          EVT
-          export GITHUB_EVENT_PATH=/tmp/run/event.json
-
-          export PATH=/tmp/stub:$PATH
-          base_url='https://raw.githubusercontent.com/oasdiff-test/test/main/simple.yaml'
-          out=$(./breaking/entrypoint.sh \
-            "$base_url" 'simple.yaml' \
-            '' '' '' '' '' '' '' '' '' '' '' '' 2>&1)
-          echo "--- entrypoint output ---"
-          echo "$out"
-
-          if ! echo "$out" | grep -q "::notice::.*breaking changes"; then
-            echo "FAIL: review-URL notice line missing" >&2
+          echo "review_url=$REVIEW_URL"
+          if [ -z "$REVIEW_URL" ]; then
+            echo "FAIL: review_url output is empty (expected breaking changes to fire the notice)" >&2
             exit 1
           fi
-          notice=$(echo "$out" | grep "::notice::.*breaking changes")
-          if echo "$notice" | grep -q 'base_file=https%3A%2F%2Fraw.githubusercontent.com'; then
+          if printf '%s' "$REVIEW_URL" | grep -q 'base_file=https%3A%2F%2Fraw.githubusercontent.com'; then
             echo "PASS: full https://raw... URL preserved in base_file"
-          elif echo "$notice" | grep -q 'base_file=%2F%2Fraw.githubusercontent.com'; then
+          elif printf '%s' "$REVIEW_URL" | grep -q 'base_file=%2F%2Fraw.githubusercontent.com'; then
             echo "FAIL: 'https:' was stripped from base, the strip_ref_prefix URL guard is missing" >&2
-            echo "notice line: $notice" >&2
             exit 1
           else
-            echo "FAIL: base_file= param did not contain the raw.githubusercontent.com host as expected" >&2
-            echo "notice line: $notice" >&2
+            echo "FAIL: base_file= did not contain the raw.githubusercontent.com host as expected" >&2
             exit 1
           fi
 
   breaking_free_review_url_strips_git_ref_prefix:
     runs-on: ubuntu-latest
-    name: "Test breaking free review URL strips origin/main: prefix from git-ref base"
-    # Companion to breaking_free_review_url_preserves_https_base: a git-ref
-    # base (origin/main:openapi.yaml) must still have its prefix stripped so
-    # the /review page receives just the path.
+    name: "Test breaking free review URL strips the ref: prefix from a git-ref base"
+    # Companion to the preserve test: a git-ref base (HEAD:specs/base.yaml) must
+    # have its ref prefix stripped so base_file is just the path. Also exercises
+    # real git-ref resolution, the action's recommended base form.
     steps:
       - uses: actions/checkout@v6
-      - name: Stub oasdiff to report a change so the notice fires
+      - uses: ./breaking
+        id: brk
+        with:
+          base: 'HEAD:specs/base.yaml'
+          revision: 'specs/revision-breaking.yaml'
+      - name: Assert the git-ref prefix is stripped from base_file
+        env:
+          REVIEW_URL: ${{ steps.brk.outputs.review_url }}
         run: |
           set -euo pipefail
-          mkdir -p /tmp/stub
-          cat > /tmp/stub/oasdiff <<'STUB'
-          #!/bin/sh
-          echo '1 breaking change(s)'
-          STUB
-          chmod +x /tmp/stub/oasdiff
-
-          mkdir -p /tmp/run
-          export GITHUB_REPOSITORY=foo/bar
-          export GITHUB_SHA=deadbeef
-          export GITHUB_BASE_REF=main
-          export GITHUB_OUTPUT=/tmp/run/github-output
-          export GITHUB_STEP_SUMMARY=/tmp/run/step-summary
-          cat > /tmp/run/event.json <<EVT
-          {"pull_request":{"head":{"sha":"deadbeef"},"base":{"sha":"baadcafe"}}}
-          EVT
-          export GITHUB_EVENT_PATH=/tmp/run/event.json
-
-          export PATH=/tmp/stub:$PATH
-          out=$(./breaking/entrypoint.sh \
-            'origin/main:multi-file/openapi.yaml' 'HEAD:multi-file/openapi.yaml' \
-            '' '' '' '' '' '' '' '' '' '' '' '' 2>&1)
-          echo "--- entrypoint output ---"
-          echo "$out"
-
-          if ! echo "$out" | grep -q "::notice::.*breaking changes"; then
-            echo "FAIL: review-URL notice line missing" >&2
+          echo "review_url=$REVIEW_URL"
+          if [ -z "$REVIEW_URL" ]; then
+            echo "FAIL: review_url output is empty (expected breaking changes to fire the notice)" >&2
             exit 1
           fi
-          notice=$(echo "$out" | grep "::notice::.*breaking changes")
-          if echo "$notice" | grep -q 'base_file=multi-file%2Fopenapi.yaml'; then
-            echo "PASS: origin/main: prefix stripped from base"
+          if printf '%s' "$REVIEW_URL" | grep -q 'base_file=specs%2Fbase.yaml'; then
+            echo "PASS: ref prefix stripped from base"
           else
-            echo "FAIL: base_file= did not have the git-ref prefix stripped" >&2
-            echo "notice line: $notice" >&2
+            echo "FAIL: base_file= did not have the git-ref prefix stripped (got: $REVIEW_URL)" >&2
             exit 1
           fi
 

.github/workflows/test-changelog.yaml

@@ -90,106 +90,64 @@ jobs:
   changelog_free_review_url_preserves_https_base:
     runs-on: ubuntu-latest
     name: Test changelog free review URL keeps the https:// scheme on URL-style base
-    # Regression test for the bug class fixed in pr-comment (#120): a
-    # URL-shaped base must survive intact in the free /review link rather
-    # than being mangled to "//raw.github..." by the naive ref-prefix strip.
+    # Regression test for the bug fixed in pr-comment (#120): a URL-shaped base
+    # must survive intact in the review URL's base_file. Runs the real action in
+    # its Alpine container (the production platform) and asserts on the
+    # review_url output.
     steps:
       - uses: actions/checkout@v6
-      - name: Stub oasdiff to report a change so the notice fires
+      - uses: ./changelog
+        id: clog
+        with:
+          base: 'https://raw.githubusercontent.com/oasdiff/oasdiff/main/data/openapi-test1.yaml'
+          revision: 'https://raw.githubusercontent.com/oasdiff/oasdiff/main/data/openapi-test3.yaml'
+      - name: Assert the full https:// URL is preserved in base_file
+        env:
+          REVIEW_URL: ${{ steps.clog.outputs.review_url }}
         run: |
           set -euo pipefail
-          mkdir -p /tmp/stub
-          cat > /tmp/stub/oasdiff <<'STUB'
-          #!/bin/sh
-          echo '1 change(s)'
-          STUB
-          chmod +x /tmp/stub/oasdiff
-
-          mkdir -p /tmp/run
-          export GITHUB_REPOSITORY=oasdiff-test/test
-          export GITHUB_SHA=deadbeef
-          export GITHUB_BASE_REF=main
-          export GITHUB_OUTPUT=/tmp/run/github-output
-          export GITHUB_STEP_SUMMARY=/tmp/run/step-summary
-          cat > /tmp/run/event.json <<EVT
-          {"pull_request":{"head":{"sha":"deadbeef"},"base":{"sha":"baadcafe"}}}
-          EVT
-          export GITHUB_EVENT_PATH=/tmp/run/event.json
-
-          export PATH=/tmp/stub:$PATH
-          base_url='https://raw.githubusercontent.com/oasdiff-test/test/main/simple.yaml'
-          # Invoke with bash: the entrypoint's #!/bin/sh is dash on the runner,
-          # which rejects `set -o pipefail` (exit 2). In production it runs under
-          # the container's busybox ash, which supports it.
-          out=$(bash ./changelog/entrypoint.sh \
-            "$base_url" 'simple.yaml' \
-            '' '' '' '' '' '' '' '' '' '' '' '' 2>&1)
-          echo "--- entrypoint output ---"
-          echo "$out"
-
-          if ! echo "$out" | grep -q "::notice::.*API changes"; then
-            echo "FAIL: review-URL notice line missing" >&2
+          echo "review_url=$REVIEW_URL"
+          if [ -z "$REVIEW_URL" ]; then
+            echo "FAIL: review_url output is empty (expected changes to fire the notice)" >&2
             exit 1
           fi
-          notice=$(echo "$out" | grep "::notice::.*API changes")
-          if echo "$notice" | grep -q 'base_file=https%3A%2F%2Fraw.githubusercontent.com'; then
+          if printf '%s' "$REVIEW_URL" | grep -q 'base_file=https%3A%2F%2Fraw.githubusercontent.com'; then
             echo "PASS: full https://raw... URL preserved in base_file"
-          elif echo "$notice" | grep -q 'base_file=%2F%2Fraw.githubusercontent.com'; then
+          elif printf '%s' "$REVIEW_URL" | grep -q 'base_file=%2F%2Fraw.githubusercontent.com'; then
             echo "FAIL: 'https:' was stripped from base, the strip_ref_prefix URL guard is missing" >&2
-            echo "notice line: $notice" >&2
             exit 1
           else
-            echo "FAIL: base_file= param did not contain the raw.githubusercontent.com host as expected" >&2
-            echo "notice line: $notice" >&2
+            echo "FAIL: base_file= did not contain the raw.githubusercontent.com host as expected" >&2
             exit 1
           fi
 
   changelog_free_review_url_strips_git_ref_prefix:
     runs-on: ubuntu-latest
-    name: "Test changelog free review URL strips origin/main: prefix from git-ref base"
-    # Companion: git-ref base must have its prefix stripped to a bare path.
+    name: "Test changelog free review URL strips the ref: prefix from a git-ref base"
+    # Companion to the preserve test: a git-ref base (HEAD:specs/base.yaml) must
+    # have its ref prefix stripped so base_file is just the path. Also exercises
+    # real git-ref resolution, the action's recommended base form.
     steps:
       - uses: actions/checkout@v6
-      - name: Stub oasdiff to report a change so the notice fires
+      - uses: ./changelog
+        id: clog
+        with:
+          base: 'HEAD:specs/base.yaml'
+          revision: 'specs/revision-breaking.yaml'
+      - name: Assert the git-ref prefix is stripped from base_file
+        env:
+          REVIEW_URL: ${{ steps.clog.outputs.review_url }}
         run: |
           set -euo pipefail
-          mkdir -p /tmp/stub
-          cat > /tmp/stub/oasdiff <<'STUB'
-          #!/bin/sh
-          echo '1 change(s)'
-          STUB
-          chmod +x /tmp/stub/oasdiff
-
-          mkdir -p /tmp/run
-          export GITHUB_REPOSITORY=foo/bar
-          export GITHUB_SHA=deadbeef
-          export GITHUB_BASE_REF=main
-          export GITHUB_OUTPUT=/tmp/run/github-output
-          export GITHUB_STEP_SUMMARY=/tmp/run/step-summary
-          cat > /tmp/run/event.json <<EVT
-          {"pull_request":{"head":{"sha":"deadbeef"},"base":{"sha":"baadcafe"}}}
-          EVT
-          export GITHUB_EVENT_PATH=/tmp/run/event.json
-
-          export PATH=/tmp/stub:$PATH
-          # Invoke with bash (see the companion job): dash on the runner rejects
-          # the entrypoint's `set -o pipefail`.
-          out=$(bash ./changelog/entrypoint.sh \
-            'origin/main:multi-file/openapi.yaml' 'HEAD:multi-file/openapi.yaml' \
-            '' '' '' '' '' '' '' '' '' '' '' '' 2>&1)
-          echo "--- entrypoint output ---"
-          echo "$out"
-
-          if ! echo "$out" | grep -q "::notice::.*API changes"; then
-            echo "FAIL: review-URL notice line missing" >&2
+          echo "review_url=$REVIEW_URL"
+          if [ -z "$REVIEW_URL" ]; then
+            echo "FAIL: review_url output is empty (expected changes to fire the notice)" >&2
             exit 1
           fi
-          notice=$(echo "$out" | grep "::notice::.*API changes")
-          if echo "$notice" | grep -q 'base_file=multi-file%2Fopenapi.yaml'; then
-            echo "PASS: origin/main: prefix stripped from base"
+          if printf '%s' "$REVIEW_URL" | grep -q 'base_file=specs%2Fbase.yaml'; then
+            echo "PASS: ref prefix stripped from base"
           else
-            echo "FAIL: base_file= did not have the git-ref prefix stripped" >&2
-            echo "notice line: $notice" >&2
+            echo "FAIL: base_file= did not have the git-ref prefix stripped (got: $REVIEW_URL)" >&2
             exit 1
           fi
 

breaking/action.yml

@@ -55,6 +55,8 @@ inputs:
 outputs:
   breaking:
     description: 'Output summary of API breaking changes, encompassing both warnings and errors'
+  review_url:
+    description: 'URL of the free oasdiff review page for these changes (empty when there are no breaking changes)'
 runs:
   using: 'docker'
   image: 'Dockerfile'

breaking/entrypoint.sh

@@ -22,23 +22,22 @@ readonly warn_ignore="${13}"
 readonly output_to_file="${14}"
 
 write_output () {
-    _write_output_output="$1"
+    local output="$1"
     if [ -n "$output_to_file" ]; then
-        _write_output_file_output="$2"
-        if [ -z "$_write_output_file_output" ]; then
-            _write_output_file_output=$_write_output_output
-
+        local file_output="$2"
+        if [ -z "$file_output" ]; then
+            file_output=$output
         fi
-        echo "$_write_output_file_output" >> "$output_to_file"
+        echo "$file_output" >> "$output_to_file"
     fi
     # github-action limits output to 1MB
     # we count bytes because unicode has multibyte characters
-    size=$(echo "$_write_output_output" | wc -c)
+    size=$(echo "$output" | wc -c)
     if [ "$size" -ge "1000000" ]; then
         echo "WARN: diff exceeds the 1MB limit, truncating output..." >&2
-        _write_output_output=$(echo "$_write_output_output" | head -c 1000000)
+        output=$(echo "$output" | head -c 1000000)
     fi
-    echo "$_write_output_output" >>"$GITHUB_OUTPUT"
+    echo "$output" >>"$GITHUB_OUTPUT"
 }
 
 echo "running oasdiff breaking... base: $base, revision: $revision, fail_on: $fail_on, include_checks: $include_checks, include_path_params: $include_path_params, deprecation_days_beta: $deprecation_days_beta, deprecation_days_stable: $deprecation_days_stable, exclude_elements: $exclude_elements, filter_extension: $filter_extension, composed: $composed, flatten_allof: $flatten_allof, err_ignore: $err_ignore, warn_ignore: $warn_ignore, output_to_file: $output_to_file"
@@ -127,7 +126,7 @@ if [ -n "$breaking_changes" ] && ! echo "$breaking_changes" | head -n 1 | grep -
     if [ -z "$head_sha" ]; then head_sha="$GITHUB_SHA"; fi
     # base_sha must be an immutable commit SHA, not the branch name. Using
     # $GITHUB_BASE_REF (the branch) makes the URL decay whenever the branch
-    # advances past the file's commit — e.g. someone merges a rename of the
+    # advances past the file's commit, e.g. someone merges a rename of the
     # spec file and every previously-emitted /review URL starts 404'ing
     # because raw.githubusercontent.com now resolves the branch to a newer
     # commit where the file lives at a different path.
@@ -141,5 +140,9 @@ else
 fi
 
 echo "$delimiter" >>"$GITHUB_OUTPUT"
+# review_url is a single-line output, written after the multiline `breaking`
+# block is closed so it doesn't get folded into that value. Empty when there
+# are no breaking changes (the notice/URL only fire then).
+echo "review_url=${free_review_url:-}" >> "$GITHUB_OUTPUT"
 
 exit $exit_code

changelog/action.yml

@@ -58,6 +58,8 @@ inputs:
 outputs:
   changelog:
     description: 'Output summary of API changelog'
+  review_url:
+    description: 'URL of the free oasdiff review page for these changes (empty when there are no changes)'
 runs:
   using: 'docker'
   image: 'Dockerfile'

changelog/entrypoint.sh

@@ -79,8 +79,6 @@ if [ -n "$level" ]; then
 fi
 echo "flags: $flags"
 
-set -o pipefail
-
 # *** github action step output ***
 
 # output name should be in the syntax of multiple lines:
@@ -119,8 +117,10 @@ if [ -n "$output" ] && ! echo "$output" | head -n 1 | grep -q "^No "; then
     if [ -z "$head_sha" ]; then head_sha="$GITHUB_SHA"; fi
     # base_sha must be an immutable commit SHA, not the branch name. Using
     # $GITHUB_BASE_REF (the branch) makes the URL decay whenever the branch
-    # advances past the file's commit. See breaking/entrypoint.sh for the
-    # full rationale.
+    # advances past the file's commit, e.g. someone merges a rename of the
+    # spec file and every previously-emitted /review URL starts 404'ing
+    # because raw.githubusercontent.com now resolves the branch to a newer
+    # commit where the file lives at a different path.
     base_sha=$(jq -r '.pull_request.base.sha // empty' "$GITHUB_EVENT_PATH" 2>/dev/null || echo "")
     if [ -z "$base_sha" ]; then base_sha=$(git rev-parse "origin/$GITHUB_BASE_REF" 2>/dev/null || echo "$GITHUB_BASE_REF"); fi
     free_review_url="https://www.oasdiff.com/review?owner=${owner}&repo=${repo}&base_sha=$(urlencode "$base_sha")&rev_sha=${head_sha}&base_file=$(urlencode "$base_path")&rev_file=$(urlencode "$rev_path")"
@@ -131,6 +131,10 @@ else
 fi
 
 echo "$delimiter" >>"$GITHUB_OUTPUT"
+# review_url is a single-line output, written after the multiline `changelog`
+# block is closed so it doesn't get folded into that value. Empty when there
+# are no changes (the notice/URL only fire then).
+echo "review_url=${free_review_url:-}" >> "$GITHUB_OUTPUT"
 
 # *** github action step output ***
 

diff/entrypoint.sh

@@ -73,8 +73,6 @@ echo "flags: $flags"
 delimiter=$(cat /proc/sys/kernel/random/uuid | tr -d '-')
 echo "diff<<$delimiter" >>"$GITHUB_OUTPUT"
 
-set -o pipefail
-
 # Capture the exit code from oasdiff command while still getting the output
 exit_code=0
 if [ -n "$flags" ]; then