Fleshing Out Examples for Preview Driven Development

android/app/src/main/java/com/emergetools/hackernews/data/Dates.kt

@@ -1,6 +1,9 @@
 package com.emergetools.hackernews.data
 
 import java.time.Instant
+import java.time.LocalDateTime
+import java.time.ZoneOffset
+import java.time.format.DateTimeFormatter
 
 /**
  * Convert the difference between two epoch second times
@@ -24,6 +27,28 @@ fun relativeTimeStamp(epochSeconds: Long): String {
   return "${days.toInt()}d ago"
 }
 
+fun relativeTimeStamp(date: String): String {
+  val dateEpochs = LocalDateTime
+    .parse(date, DateTimeFormatter.ISO_DATE_TIME)
+    .toInstant(ZoneOffset.UTC)
+    .epochSecond
+  val now = Instant.now().epochSecond
+  val difference = now - dateEpochs
+
+  val minutes = difference / SECONDS_IN_MINUTE
+  if (minutes < 60) {
+    return "${minutes.toInt()}m ago"
+  }
+
+  val hours = minutes / MINUTES_IN_HOUR
+  if (hours < 24) {
+    return "${hours.toInt()}h ago"
+  }
+
+  val days = hours / HOURS_IN_DAY
+  return "${days.toInt()}d ago"
+}
+
 private const val SECONDS_IN_MINUTE = 60.0
 private const val MINUTES_IN_HOUR = 60.0
 private const val HOURS_IN_DAY = 24.0

android/app/src/main/java/com/emergetools/hackernews/features/comments/CommentsDomain.kt

@@ -114,7 +114,7 @@ sealed interface CommentState {
     val id: Long,
     val author: String,
     val content: String,
-    val epochSeconds: Long,
+    val age: String,
     val upvoted: Boolean,
     val upvoteUrl: String,
     override val children: List<CommentState>,
@@ -352,9 +352,7 @@ class CommentsViewModel(
       id = id,
       author = user,
       content = text,
-      epochSeconds = LocalDateTime
-        .parse(age, DateTimeFormatter.ISO_DATE_TIME)
-        .toInstant(ZoneOffset.UTC).epochSecond,
+      age = age,
       upvoted = upvoted,
       upvoteUrl = upvoteUrl,
       level = level,

android/app/src/main/java/com/emergetools/hackernews/features/comments/CommentsScreen.kt

@@ -42,8 +42,8 @@ fun CommentsScreen(
 ) {
   Box(
     modifier = Modifier
-        .fillMaxSize()
-        .background(color = MaterialTheme.colorScheme.background),
+      .fillMaxSize()
+      .background(color = MaterialTheme.colorScheme.background),
   ) {
     LazyColumn(
       modifier = Modifier.fillMaxSize(),
@@ -54,8 +54,8 @@ fun CommentsScreen(
         CommentsHeader(
           state = state.headerState,
           modifier = Modifier
-              .fillMaxWidth()
-              .wrapContentHeight(),
+            .fillMaxWidth()
+            .wrapContentHeight(),
           onLikeTapped = { item ->
             if (state is CommentsState.Content && state.loggedIn) {
               actions(
@@ -74,23 +74,23 @@ fun CommentsScreen(
       item {
         val lineColor = MaterialTheme.colorScheme.onBackground
         Box(modifier = Modifier
-            .fillMaxWidth()
-            .padding(horizontal = 8.dp)
-            .height(16.dp)
-            .drawBehind {
-                val lineStart = Offset(0f, size.center.y)
-                val lineEnd = Offset(size.width, size.center.y)
-                drawLine(
-                    start = lineStart,
-                    end = lineEnd,
-                    color = lineColor,
-                    strokeWidth = 4f,
-                    cap = StrokeCap.Round,
-                    pathEffect = PathEffect.dashPathEffect(
-                        intervals = floatArrayOf(10f, 10f)
-                    )
-                )
-            }
+          .fillMaxWidth()
+          .padding(horizontal = 8.dp)
+          .height(16.dp)
+          .drawBehind {
+            val lineStart = Offset(0f, size.center.y)
+            val lineEnd = Offset(size.width, size.center.y)
+            drawLine(
+              start = lineStart,
+              end = lineEnd,
+              color = lineColor,
+              strokeWidth = 4f,
+              cap = StrokeCap.Round,
+              pathEffect = PathEffect.dashPathEffect(
+                intervals = floatArrayOf(10f, 10f)
+              )
+            )
+          }
         )
       }
       items(items = state.comments.filter { it.hidden != HiddenStatus.HiddenByParent }) { comment ->
@@ -171,7 +171,7 @@ private fun CommentsScreenPreview() {
             level = 0,
             author = "rikinm",
             content = "Hello Child",
-            epochSeconds = Instant.now().minusSeconds(60 * 60 * 24 * 2).epochSecond,
+            age = "2024-09-05T17:48:25",
             upvoted = false,
             upvoteUrl = "",
             children = listOf()
@@ -181,7 +181,7 @@ private fun CommentsScreenPreview() {
             level = 1,
             author = "vasantm",
             content = "Hello Parent",
-            epochSeconds = Instant.now().minusSeconds(60 * 60 * 1).epochSecond,
+            age = "2024-09-05T17:48:25",
             upvoted = false,
             upvoteUrl = "",
             children = listOf()
@@ -230,7 +230,7 @@ fun CommentsScreenAppStorePreview() {
             level = 0,
             author = "rikinm",
             content = "My question is: why do an Oral-B app and a Colgate app even exist?",
-            epochSeconds = Instant.now().minusSeconds(60 * 60 * 2).epochSecond,
+            age = "2024-09-05T17:48:25",
             upvoted = false,
             upvoteUrl = "",
             children = listOf()
@@ -240,7 +240,7 @@ fun CommentsScreenAppStorePreview() {
             level = 1,
             author = "telkins",
             content = "The same reason they now have a toothbrush with AI. Because they are in a race to continuously re-invent the toothbrush every year to create new USPs, create new marketing angles and keep sales high.",
-            epochSeconds = Instant.now().minusSeconds(60 * 60 * 2).epochSecond,
+            age = "2024-09-05T17:48:25",
             upvoted = false,
             upvoteUrl = "",
             children = listOf()
@@ -250,7 +250,7 @@ fun CommentsScreenAppStorePreview() {
             level = 2,
             author = "nhinderling",
             content = "I'm surprised that health insurance companies haven't started offering \"good brusher\" discounts the way car insurance companies offer a \"good driver\" discount when you use their car data logging device/app.",
-            epochSeconds = Instant.now().minusSeconds(60 * 60 * 1).epochSecond,
+            age = "2024-09-05T17:48:25",
             upvoted = false,
             upvoteUrl = "",
             children = listOf()
@@ -262,7 +262,7 @@ fun CommentsScreenAppStorePreview() {
             author = "vasantm",
             content = "So it’s all just stupidly big PDFs used as images of the different models?\n" +
               "Not what I was expecting. I was expecting it to be more like the Colgate app mentioned later in thread.",
-            epochSeconds = Instant.now().minusSeconds(60 * 60 * 2).epochSecond,
+            age = "2024-09-05T17:48:25",
             upvoted = false,
             upvoteUrl = "",
             children = listOf()
@@ -272,7 +272,7 @@ fun CommentsScreenAppStorePreview() {
             level = 1,
             author = "itaybre",
             content = "I wonder if they generated the PDFs with a web browser's Print to PDF feature. Chrome's PDFs are massive.",
-            epochSeconds = Instant.now().minusSeconds(60 * 60 * 1).epochSecond,
+            age = "2024-09-05T17:48:25",
             upvoted = false,
             upvoteUrl = "",
             children = listOf()
@@ -282,7 +282,7 @@ fun CommentsScreenAppStorePreview() {
             level = 1,
             author = "chromy",
             content = "That’s insane. They should absolutely, 100% be pulled on demand.",
-            epochSeconds = Instant.now().minusSeconds(60 * 60 * 1).epochSecond,
+            age = "2024-09-05T17:48:25",
             upvoted = false,
             upvoteUrl = "",
             children = listOf()
@@ -293,7 +293,7 @@ fun CommentsScreenAppStorePreview() {
             author = "mptop27",
             content = "I think there’s nothing wrong with shipping the images, why should you need an Internet connection to pair your toothbrush (which of your using the app you must want to do).\n" +
               "But why can’t they be vector images? The pictures in the tweet looks like they could easily be replaced by vectors and the difference would be nearly unnoticeable.",
-            epochSeconds = Instant.now().minusSeconds(60 * 30).epochSecond,
+            age = "2024-09-05T17:48:25",
             upvoted = false,
             upvoteUrl = "",
             children = listOf()

android/app/src/main/java/com/emergetools/hackernews/features/comments/components/CommentRow.kt

@@ -33,6 +33,7 @@ import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.tooling.preview.PreviewLightDark
 import androidx.compose.ui.unit.dp
 import com.emergetools.hackernews.R
@@ -43,7 +44,6 @@ import com.emergetools.hackernews.ui.components.MetadataTag
 import com.emergetools.hackernews.ui.theme.HackerGreen
 import com.emergetools.hackernews.ui.theme.HackerNewsTheme
 import com.emergetools.hackernews.ui.util.parseAsHtml
-import java.time.Instant
 
 @Composable
 fun CommentRow(
@@ -78,7 +78,7 @@ fun CommentRow(
             fontWeight = FontWeight.Bold
           )
           MetadataTag(
-            label = relativeTimeStamp(state.epochSeconds),
+            label = relativeTimeStamp(state.age),
           ) {
             Icon(
               modifier = Modifier.size(12.dp),
@@ -237,7 +237,7 @@ fun CommentRowPreview() {
           level = 0,
           author = "rikinm",
           content = "Hello Parent",
-          epochSeconds = Instant.now().minusSeconds(60 * 60 * 2).epochSecond,
+          age = "2024-09-05T17:48:25",
           upvoted = false,
           upvoteUrl = "",
           children = listOf()
@@ -263,3 +263,27 @@ fun CommentRowLoadingPreview() {
   }
 }
 
+@Preview
+@Composable
+private fun TestIsoDateTimeParsing() {
+  HackerNewsTheme {
+    Column {
+      val isoDateWithTimeZone = "2024-09-05T17:48:25.000000Z"
+      CommentRow(
+        state = CommentState.Content(
+          id = 1,
+          level = 0,
+          author = "rikinm",
+          content = "Hello Parent",
+          age = isoDateWithTimeZone,
+          upvoted = false,
+          upvoteUrl = "",
+          children = listOf()
+        ),
+        onToggleHide = {},
+        onLikeTapped = {}
+      )
+    }
+  }
+}
+