diff --git a/src/test/groovy/sdkman/specs/InstallSpec.groovy b/src/test/groovy/sdkman/specs/InstallSpec.groovy
index 15359d71..bb5adbcd 100644
--- a/src/test/groovy/sdkman/specs/InstallSpec.groovy
+++ b/src/test/groovy/sdkman/specs/InstallSpec.groovy
@@ -41,6 +41,160 @@ class InstallSpec extends Specification {
         sdkmanInitScript.exists()
     }
 
+    void "should skip installation if SDKMAN has been already installed"() {
+        given:
+        new File(sdkmanBaseDir, ".sdkman").mkdirs()
+
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        bash.output.contains('You already have SDKMAN installed')
+    }
+
+    void "should store version in var/version file"() {
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        bash.execute("cat ${sdkmanBaseDir}/.sdkman/var/version")
+        bash.output.trim() == 'x.y.z'
+    }
+
+    void "should update existing bash_profile when sdkman snippet is not present"() {
+        given:
+        new File(sdkmanBaseDir, ".bash_profile").createNewFile()
+
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        bash.output.contains("Updated existing ${sdkmanBaseDir}/.bash_profile")
+        bash.execute("cat ${sdkmanBaseDir}/.bash_profile")
+        bash.output.contains('#THIS MUST BE AT THE END OF THE FILE FOR SDKMAN TO WORK!!!')
+    }
+
+    void "should skip updating existing bash_profile when sdkman snippet is present"() {
+        given:
+        def file = new File(sdkmanBaseDir, ".bash_profile")
+        file.createNewFile()
+        file.write "sdkman-init.sh"
+
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        !bash.output.contains("Updated existing ${sdkmanBaseDir}/.bash_profile")
+    }
+
+    void "should update existing profile when sdkman snippet is not present"() {
+        given:
+        new File(sdkmanBaseDir, ".profile").createNewFile()
+
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        bash.output.contains("Updated existing ${sdkmanBaseDir}/.profile")
+        bash.execute("cat ${sdkmanBaseDir}/.profile")
+        bash.output.contains('#THIS MUST BE AT THE END OF THE FILE FOR SDKMAN TO WORK!!!')
+    }
+
+    void "should skip updating existing profile when sdkman snippet is present"() {
+        given:
+        def file = new File(sdkmanBaseDir, ".profile")
+        file.createNewFile()
+        file.write "sdkman-init.sh"
+
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        !bash.output.contains("Updated existing ${sdkmanBaseDir}/.profile")
+    }
+
+    void "should update existing bashrc when sdkman snippet is not present"() {
+        given:
+        new File(sdkmanBaseDir, ".bashrc").createNewFile()
+
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        bash.output.contains("Updated existing ${sdkmanBaseDir}/.bashrc")
+        bash.execute("cat ${sdkmanBaseDir}/.bashrc")
+        bash.output.contains('#THIS MUST BE AT THE END OF THE FILE FOR SDKMAN TO WORK!!!')
+    }
+
+    void "should skip updating existing bashrc when sdkman snippet is present"() {
+        given:
+        def file = new File(sdkmanBaseDir, ".bashrc")
+        file.createNewFile()
+        file.write "sdkman-init.sh"
+
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        !bash.output.contains("Updated existing ${sdkmanBaseDir}/.bashrc")
+    }
+
+    void "should update existing zshrc when sdkman snippet is not present"() {
+        given:
+        new File(sdkmanBaseDir, ".zshrc").createNewFile()
+
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        bash.output.contains("Updated existing ${sdkmanBaseDir}/.zshrc")
+        bash.execute("cat ${sdkmanBaseDir}/.zshrc")
+        bash.output.contains('#THIS MUST BE AT THE END OF THE FILE FOR SDKMAN TO WORK!!!')
+    }
+
+    void "should skip updating existing zshrc when sdkman snippet is present"() {
+        given:
+        def file = new File(sdkmanBaseDir, ".zshrc")
+        file.createNewFile()
+        file.write "sdkman-init.sh"
+
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        !bash.output.contains("Updated existing ${sdkmanBaseDir}/.zshrc")
+    }
+
+    void "should create bash_profile when not present"() {
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        bash.output.contains("Created and initialised ${sdkmanBaseDir}/.bash_profile")
+        bash.execute("cat ${sdkmanBaseDir}/.bash_profile")
+        bash.output.contains('#THIS MUST BE AT THE END OF THE FILE FOR SDKMAN TO WORK!!!')
+    }
+
+    void "should create bashrc when not present"() {
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        bash.output.contains("Created and initialised ${sdkmanBaseDir}/.bashrc")
+        bash.execute("cat ${sdkmanBaseDir}/.bashrc")
+        bash.output.contains('#THIS MUST BE AT THE END OF THE FILE FOR SDKMAN TO WORK!!!')
+    }
+
+    void "should create zshrc when not present"() {
+        when:
+        bash.execute("curl -s ${service} | bash")
+
+        then:
+        bash.output.contains("Created and initialised ${sdkmanBaseDir}/.zshrc")
+        bash.execute("cat ${sdkmanBaseDir}/.zshrc")
+        bash.output.contains('#THIS MUST BE AT THE END OF THE FILE FOR SDKMAN TO WORK!!!')
+    }
+
     private static primeInstallScriptEndpoint() {
         primeEndpointWithString("/", ("build/testScripts/install.sh" as File).text)
     }