[Tests] Add markdown-link-check test

This test use the npm package: markdown-link-check to help check if all
the links in the documentation is alive.

.travis.yml

@@ -19,11 +19,12 @@ before_install:
   - curl --version
   - wget --version
 install:
-  - if [ -z "${SHELLCHECK-}" ]; then nvm install node && npm install && npm prune && npm ls urchin doctoc; fi
+  - if [ -z "${SHELLCHECK-}" ]; then nvm install node && npm install && npm prune && npm ls urchin doctoc markdown-link-check; fi
   - '[ -z "$WITHOUT_CURL" ] || sudo apt-get remove curl -y'
 script:
   - if [ -n "${MAKE_RELEASE-}" ]; then export GIT_EDITOR="sed -i '1 s/^/99.99.99 make release test/'" && git fetch --unshallow --tags && echo proceed | make TAG=99.99.99 release ; fi
   - if [ -n "${DOCTOCCHECK-}" ]; then cp README.md README.md.orig && npm run doctoc && diff -q README.md README.md.orig ; fi
+  - if [ -n "${MARKDOWN_LINK_CHECK-}" ]; then npm run markdown-link-check ; fi
   - if [ -n "${SHELLCHECK-}" ]; then shellcheck -s bash nvm.sh && shellcheck -s sh nvm.sh && shellcheck -s dash nvm.sh && shellcheck -s ksh nvm.sh ; fi
   - if [ -n "${SHELLCHECK-}" ]; then shellcheck -s bash install.sh bash_completion nvm-exec ; fi
   - if [ -n "${SHELL-}" ] && [ -n "${TEST_SUITE}" ]; then if [ "${TEST_SUITE}" = 'installation_iojs' ]; then travis_retry make TEST_SUITE=$TEST_SUITE URCHIN="$(npm bin)/urchin" test-$SHELL ; else make TEST_SUITE=$TEST_SUITE URCHIN="$(npm bin)/urchin" test-$SHELL; fi; fi
@@ -38,6 +39,7 @@ env:
   matrix:
     - MAKE_RELEASE=true
     - DOCTOCCHECK=true
+    - MARKDOWN_LINK_CHECK=true
     - SHELLCHECK=true
     - SHELL=bash TEST_SUITE=install_script
     - SHELL=sh TEST_SUITE=fast

package.json

@@ -14,7 +14,8 @@
     "test/installation/node": "shell=$(basename -- $(ps -o comm= $(ps -o ppid= -p $PPID)) | sed 's/^-//'); make TEST_SUITE=installation_node test-$shell",
     "test/installation/iojs": "shell=$(basename -- $(ps -o comm= $(ps -o ppid= -p $PPID)) | sed 's/^-//'); make TEST_SUITE=installation_iojs test-$shell",
     "test/sourcing": "shell=$(basename -- $(ps -o comm= $(ps -o ppid= -p $PPID)) | sed 's/^-//'); make TEST_SUITE=sourcing test-$shell",
-    "doctoc": "doctoc --title='## Table of Contents' --github README.md"
+    "doctoc": "doctoc --title='## Table of Contents' --github README.md",
+    "markdown-link-check": "find . -type f -name '*.md' | grep -v '^./node_modules\\|^./v' | xargs -n 1 markdown-link-check -p"
   },
   "repository": {
     "type": "git",
@@ -37,6 +38,7 @@
     "replace": "^0.3.0",
     "semver": "^5.0.1",
     "urchin": "^0.0.5",
-    "doctoc": "^1.2.0"
+    "doctoc": "^1.2.0",
+    "markdown-link-check": "^3.1.4"
   }
 }