Stub value substitution using a template

core/src/main/kotlin/io/specmatic/core/HttpPathPattern.kt

@@ -9,6 +9,8 @@ import java.net.URI
 
 val OMIT = listOf("(OMIT)", "(omit)")
 
+val EMPTY_PATH= HttpPathPattern(emptyList(), "")
+
 data class HttpPathPattern(
     val pathSegmentPatterns: List<URLPathSegmentPattern>,
     val path: String

core/src/main/kotlin/io/specmatic/core/HttpRequest.kt

@@ -68,9 +68,13 @@ data class HttpRequest(
             val urlParam = URI(path)
             updateWith(urlParam)
         } catch (e: URISyntaxException) {
-            copy(path = path)
+            val pieces = path.split("?", limit = 2)
+            updateWithPathAndQuery(pieces.get(0), pieces.getOrNull(1))
+//            copy(path = path)
         } catch (e: UnsupportedEncodingException) {
-            copy(path = path)
+            val pieces = path.split("?", limit = 2)
+            updateWithPathAndQuery(pieces.get(0), pieces.getOrNull(1))
+//            copy(path = path)
         }
     }
 
@@ -81,8 +85,15 @@ data class HttpRequest(
     fun updateBody(body: String?): HttpRequest = copy(body = parsedValue(body))
 
     fun updateWith(url: URI): HttpRequest {
-        val path = url.path
-        val queryParams = parseQuery(url.query)
+//        val path = url.path
+//        val queryParams = parseQuery(url.query)
+//        return copy(path = path, queryParams = QueryParameters(queryParams))
+
+        return updateWithPathAndQuery(url.path, url.query)
+    }
+
+    fun updateWithPathAndQuery(path: String, query: String?): HttpRequest {
+        val queryParams = parseQuery(query)
         return copy(path = path, queryParams = QueryParameters(queryParams))
     }
 

core/src/main/kotlin/io/specmatic/core/HttpRequestPattern.kt

@@ -731,6 +731,10 @@ data class HttpRequestPattern(
         } ?: row
     }
 
+    fun getSubstitution(request: HttpRequest, resolver: Resolver): Substitution {
+        return Substitution(request, httpPathPattern ?: HttpPathPattern(emptyList(), ""), headersPattern, httpQueryParamPattern, body, resolver)
+    }
+
 }
 
 fun missingParam(missingValue: String): ContractException {

core/src/main/kotlin/io/specmatic/core/HttpResponse.kt

@@ -1,12 +1,12 @@
 package io.specmatic.core
 
+import io.ktor.http.*
 import io.specmatic.conversions.guessType
 import io.specmatic.core.GherkinSection.Then
 import io.specmatic.core.pattern.ContractException
 import io.specmatic.core.pattern.Pattern
 import io.specmatic.core.pattern.parsedValue
 import io.specmatic.core.value.*
-import io.ktor.http.*
 
 private const val SPECMATIC_HEADER_PREFIX = "X-$APPLICATION_NAME-"
 const val SPECMATIC_RESULT_HEADER = "${SPECMATIC_HEADER_PREFIX}Result"

core/src/main/kotlin/io/specmatic/core/HttpResponsePattern.kt

@@ -157,6 +157,16 @@ data class HttpResponsePattern(
             response.body.exactMatchElseType()
         )
     }
+
+    fun resolveSubstitutions(substitution: Substitution, response: HttpResponse): HttpResponse {
+        val substitutedHeaders = substitution.resolveHeaderSubstitutions(response.headers, headersPattern.pattern).breadCrumb("RESPONSE.HEADERS").value
+        val substitutedBody = body.resolveSubstitutions(substitution, response.body, substitution.resolver).breadCrumb("RESPONSE.BODY").value
+
+        return response.copy(
+            headers = substitutedHeaders,
+            body = substitutedBody
+        )
+    }
 }
 
 private val valueMismatchMessages = object : MismatchMessages {

core/src/main/kotlin/io/specmatic/core/Scenario.kt

@@ -578,6 +578,11 @@ data class Scenario(
                     && operationId.responseStatus == status
                     && httpRequestPattern.matchesPath(operationId.requestPath, resolver).isSuccess()
         }
+
+    fun resolveSubtitutions(request: HttpRequest, response: HttpResponse): HttpResponse {
+        val substitution = httpRequestPattern.getSubstitution(request, resolver)
+        return httpResponsePattern.resolveSubstitutions(substitution, response)
+    }
 }
 
 fun newExpectedServerStateBasedOn(

core/src/main/kotlin/io/specmatic/core/SpecmaticConfig.kt

@@ -282,6 +282,7 @@ fun loadSpecmaticConfig(configFileName: String? = null): SpecmaticConfig {
         logger.log(e, "A dependency version conflict has been detected. If you are using Spring in a maven project, a common resolution is to set the property <kotlin.version></kotlin.version> to your pom project.")
         throw e
     } catch (e: Throwable) {
+        logger.log(e, "Your configuration file may have some missing configuration sections. Please ensure that the $configFileName file adheres to the schema described at: https://specmatic.io/documentation/specmatic_json.html")
         throw Exception("Your configuration file may have some missing configuration sections. Please ensure that the $configFileName file adheres to the schema described at: https://specmatic.io/documentation/specmatic_json.html", e)
     }
 }

core/src/main/kotlin/io/specmatic/core/Substitution.kt

@@ -0,0 +1,146 @@
+package io.specmatic.core
+
+import io.specmatic.core.pattern.*
+import io.specmatic.core.value.JSONArrayValue
+import io.specmatic.core.value.JSONObjectValue
+import io.specmatic.core.value.StringValue
+import io.specmatic.core.value.Value
+
+class Substitution(
+    val request: HttpRequest,
+    val httpPathPattern: HttpPathPattern,
+    val headersPattern: HttpHeadersPattern,
+    val httpQueryParamPattern: HttpQueryParamPattern,
+    val body: Pattern,
+    val resolver: Resolver
+) {
+    fun resolveSubstitutions(value: Value): Value {
+        return when(value) {
+            is JSONObjectValue -> resolveSubstitutions(value)
+            is JSONArrayValue -> resolveSubstitutions(value)
+            is StringValue -> {
+                if(value.string.startsWith("{{") && value.string.endsWith("}}"))
+                    StringValue(substitute(value.string))
+                else
+                    value
+            }
+            else -> value
+        }
+    }
+
+    fun substitute(string: String): String {
+        val expressionPath = string.removeSurrounding("{{", "}}")
+
+        val parts = expressionPath.split(".")
+
+        val area = parts.firstOrNull() ?: throw ContractException("The expression $expressionPath was empty")
+
+        return if(area.uppercase() == "REQUEST") {
+            val requestPath = parts.drop(1)
+
+            val requestPart = requestPath.firstOrNull() ?: throw ContractException("The expression $expressionPath does not include anything after REQUEST to say what has to be substituted")
+            val payloadPath = requestPath.drop(1)
+
+            val payloadKey = payloadPath.joinToString(".")
+
+            when (requestPart.uppercase()) {
+                "BODY" -> {
+                    val requestJSONBody = request.body as? JSONObjectValue
+                        ?: throw ContractException("Substitution $string cannot be resolved as the request body is not an object")
+                    requestJSONBody.findFirstChildByPath(payloadPath)?.toStringLiteral()
+                        ?: throw ContractException("Could not find $string in the request body")
+                }
+
+                "HEADERS" -> {
+                    val requestHeaders = request.headers
+                    val requestHeaderName = payloadKey
+                    requestHeaders[requestHeaderName]
+                        ?: throw ContractException("Substitution $string cannot be resolved as the request header $requestHeaderName cannot be found")
+                }
+
+                "QUERY-PARAMS" -> {
+                    val requestQueryParams = request.queryParams
+                    val requestQueryParamName = payloadKey
+                    val queryParamPair = requestQueryParams.paramPairs.find { it.first == requestQueryParamName }
+                        ?: throw ContractException("Substitution $string cannot be resolved as the request query param $requestQueryParamName cannot be found")
+
+                    queryParamPair.second
+                }
+
+                "PATH" -> {
+                    val indexOfPathParam = httpPathPattern.pathSegmentPatterns.indexOfFirst { it.key == payloadKey }
+
+                    if (indexOfPathParam < 0) throw ContractException("Could not find path param named $string")
+
+                    (request.path ?: "").split("/").let {
+                        if (it.firstOrNull() == "")
+                            it.drop(1)
+                        else
+                            it
+                    }.get(indexOfPathParam)
+                }
+
+                else -> string
+            }
+        }
+        else
+            string
+    }
+
+    private fun resolveSubstitutions(value: JSONObjectValue): Value {
+        return value.copy(
+            value.jsonObject.mapValues { entry ->
+                resolveSubstitutions(entry.value)
+            }
+        )
+    }
+
+    private fun resolveSubstitutions(value: JSONArrayValue): Value {
+        return value.copy(
+            value.list.map {
+                resolveSubstitutions(it)
+            }
+        )
+    }
+
+    fun resolveHeaderSubstitutions(map: Map<String, String>, patternMap: Map<String, Pattern>): ReturnValue<Map<String, String>> {
+        return map.mapValues { (key, value) ->
+            val string = substitute(value)
+
+            val returnValue = (patternMap.get(key) ?: patternMap.get("$key?"))?.let { pattern ->
+                try {
+                    HasValue(pattern.parse(string, resolver).toStringLiteral())
+                } catch(e: Throwable) {
+                    HasException(e)
+                }
+            } ?: HasValue(value)
+
+            returnValue.breadCrumb(key)
+        }.mapFold()
+    }
+
+    fun substitute(value: Value, pattern: Pattern): ReturnValue<Value> {
+        return try {
+            if(value !is StringValue || !hasTemplate(value.string))
+                return HasValue(value)
+
+            val updatedString = substitute(value.string)
+            HasValue(pattern.parse(updatedString, resolver))
+        } catch(e: Throwable) {
+            HasException(e)
+        }
+    }
+
+    private fun hasTemplate(string: String): Boolean {
+        return string.startsWith("{{") && string.endsWith("}}")
+    }
+
+    fun substitute(string: String, pattern: Pattern): ReturnValue<Value> {
+        return try {
+            val updatedString = substitute(string)
+            HasValue(pattern.parse(updatedString, resolver))
+        } catch(e: Throwable) {
+            HasException(e)
+        }
+    }
+}

core/src/main/kotlin/io/specmatic/core/pattern/AnyPattern.kt

@@ -1,9 +1,6 @@
 package io.specmatic.core.pattern
 
-import io.specmatic.core.MismatchMessages
-import io.specmatic.core.Resolver
-import io.specmatic.core.Result
-import io.specmatic.core.mismatchResult
+import io.specmatic.core.*
 import io.specmatic.core.pattern.config.NegativePatternConfiguration
 import io.specmatic.core.value.EmptyString
 import io.specmatic.core.value.NullValue
@@ -22,6 +19,42 @@ data class AnyPattern(
 
     data class AnyPatternMatch(val pattern: Pattern, val result: Result)
 
+    override fun resolveSubstitutions(
+        substitution: Substitution,
+        value: Value,
+        resolver: Resolver
+    ): ReturnValue<Value> {
+        val options = pattern.map {
+            it.resolveSubstitutions(substitution, value, resolver)
+        }
+
+        val hasValue = options.find { it is HasValue }
+
+        if(hasValue != null)
+            return hasValue
+
+        val failures = options.map {
+            it.realise(
+                hasValue = { _, _ ->
+                    throw NotImplementedError()
+                },
+                orFailure = { failure -> failure.failure },
+                orException = { exception -> exception.toHasFailure().failure }
+            )
+        }
+
+        return HasFailure<Value>(Result.Failure.fromFailures(failures))
+    }
+
+    override fun getTemplateTypes(key: String, value: Value, resolver: Resolver): ReturnValue<Map<String, Pattern>> {
+        val initialValue: ReturnValue<Map<String, Pattern>> = HasValue(emptyMap<String, Pattern>())
+
+        return pattern.fold(initialValue) { acc, pattern ->
+            val templateTypes = pattern.getTemplateTypes("", value, resolver)
+            acc.assimilate(templateTypes) { data, additional -> data + additional }
+        }
+    }
+
     override fun matches(sampleData: Value?, resolver: Resolver): Result {
         val matchResults = pattern.map {
             AnyPatternMatch(it, resolver.matchesPattern(key, it, sampleData ?: EmptyString))

core/src/main/kotlin/io/specmatic/core/pattern/Base64StringPattern.kt

@@ -12,6 +12,9 @@ import java.util.*
 
 data class Base64StringPattern(override val typeAlias: String? = null) : Pattern, ScalarType {
     override fun matches(sampleData: Value?, resolver: Resolver): Result {
+        if (sampleData?.hasTemplate() == true)
+            return Result.Success()
+
         return when (sampleData) {
             is StringValue -> {
                 return if (Base64.isBase64(sampleData.string)) Result.Success() else mismatchResult("string of bytes (base64)", sampleData, resolver.mismatchMessages)

core/src/main/kotlin/io/specmatic/core/pattern/BinaryPattern.kt

@@ -15,6 +15,9 @@ data class BinaryPattern(
 ) : Pattern, ScalarType {
 
     override fun matches(sampleData: Value?, resolver: Resolver): Result {
+        if (sampleData?.hasTemplate() == true)
+            return Result.Success()
+
         return when (sampleData) {
             is StringValue -> return Result.Success()
             else -> mismatchResult("string", sampleData, resolver.mismatchMessages)

core/src/main/kotlin/io/specmatic/core/pattern/BooleanPattern.kt

@@ -10,11 +10,15 @@ import io.specmatic.core.value.Value
 import java.util.*
 
 data class BooleanPattern(override val example: String? = null) : Pattern, ScalarType, HasDefaultExample {
-    override fun matches(sampleData: Value?, resolver: Resolver): Result =
-        when(sampleData) {
+    override fun matches(sampleData: Value?, resolver: Resolver): Result {
+        if (sampleData?.hasTemplate() == true)
+            return Result.Success()
+
+        return when (sampleData) {
             is BooleanValue -> Result.Success()
             else -> mismatchResult("boolean", sampleData, resolver.mismatchMessages)
         }
+    }
 
     override fun generate(resolver: Resolver): Value =
         resolver.resolveExample(example, this) ?: randomBoolean()

core/src/main/kotlin/io/specmatic/core/pattern/DatePattern.kt

@@ -8,12 +8,18 @@ import io.specmatic.core.value.StringValue
 import io.specmatic.core.value.Value
 
 object DatePattern : Pattern, ScalarType {
-    override fun matches(sampleData: Value?, resolver: Resolver): Result = when (sampleData) {
-        is StringValue -> resultOf {
-            parse(sampleData.string, resolver)
-            Result.Success()
+    override fun matches(sampleData: Value?, resolver: Resolver): Result {
+        if (sampleData?.hasTemplate() == true)
+            return Result.Success()
+
+        return when (sampleData) {
+            is StringValue -> resultOf {
+                parse(sampleData.string, resolver)
+                Result.Success()
+            }
+
+            else -> Result.Failure("Date types can only be represented using strings")
         }
-        else -> Result.Failure("Date types can only be represented using strings")
     }
 
     override fun generate(resolver: Resolver): StringValue = StringValue(RFC3339.currentDate())

core/src/main/kotlin/io/specmatic/core/pattern/DateTimePattern.kt

@@ -9,12 +9,18 @@ import io.specmatic.core.value.Value
 
 
 object DateTimePattern : Pattern, ScalarType {
-    override fun matches(sampleData: Value?, resolver: Resolver): Result = when (sampleData) {
-        is StringValue -> resultOf {
-            parse(sampleData.string, resolver)
-            Result.Success()
+    override fun matches(sampleData: Value?, resolver: Resolver): Result {
+        if (sampleData?.hasTemplate() == true)
+            return Result.Success()
+
+        return when (sampleData) {
+            is StringValue -> resultOf {
+                parse(sampleData.string, resolver)
+                Result.Success()
+            }
+
+            else -> Result.Failure("DateTime types can only be represented using strings")
         }
-        else -> Result.Failure("DateTime types can only be represented using strings")
     }
 
     override fun generate(resolver: Resolver): StringValue = StringValue(RFC3339.currentDateTime())